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2025-08-20selftests/bpf: Fix ringbuf/ringbuf_write test failure with arm64 64KB page sizeYonghong Song1-2/+2
[ Upstream commit 8c8c5e3c854a2593ec90dacd868f3066b67de1c4 ] The ringbuf max_entries must be PAGE_ALIGNED. See kernel function ringbuf_map_alloc(). So for arm64 64KB page size, adjust max_entries and other related metrics properly. Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20250607013621.1552332-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-20bpf: Make reg_not_null() true for CONST_PTR_TO_MAPIhor Solodrai1-1/+1
[ Upstream commit 5534e58f2e9bd72b253d033ee0af6e68eb8ac96b ] When reg->type is CONST_PTR_TO_MAP, it can not be null. However the verifier explores the branches under rX == 0 in check_cond_jmp_op() even if reg->type is CONST_PTR_TO_MAP, because it was not checked for in reg_not_null(). Fix this by adding CONST_PTR_TO_MAP to the set of types that are considered non nullable in reg_not_null(). An old "unpriv: cmp map pointer with zero" selftest fails with this change, because now early out correctly triggers in check_cond_jmp_op(), making the verification to pass. In practice verifier may allow pointer to null comparison in unpriv, since in many cases the relevant branch and comparison op are removed as dead code. So change the expected test result to __success_unpriv. Signed-off-by: Ihor Solodrai <isolodrai@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20250609183024.359974-2-isolodrai@meta.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-15selftests/bpf: Fix build error with llvm 19Alexei Starovoitov1-1/+1
commit 608e99f7869e3a6e028c7cba14a896c7797e8746 upstream. llvm 19 fails to compile arena self test: CLNG-BPF [test_progs] verifier_arena_large.bpf.o progs/verifier_arena_large.c:90:24: error: unsupported signed division, please convert to unsigned div/mod. 90 | pg_idx = (pg - base) / PAGE_SIZE; Though llvm <= 18 and llvm >= 20 don't have this issue, fix the test to avoid the build error. Reported-by: Jiri Olsa <olsajiri@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Yifei Liu <yifei.l.liu@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-15selftests/bpf: Add a test for arena range tree algorithmAlexei Starovoitov1-2/+108
commit e58358afa84e8e271a296459d35d1715c7572013 upstream. Add a test that verifies specific behavior of arena range tree algorithm and adjust existing big_alloc1 test due to use of global data in arena. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/bpf/20241108025616.17625-3-alexei.starovoitov@gmail.com Signed-off-by: Yifei Liu <yifei.l.liu@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-01selftests/bpf: Add tests with stack ptr register in conditional jmpYonghong Song1-0/+53
commit 5ffb537e416ee22dbfb3d552102e50da33fec7f6 upstream. Add two tests: - one test has 'rX <op> r10' where rX is not r10, and - another test has 'rX <op> rY' where rX and rY are not r10 but there is an early insn 'rX = r10'. Without previous verifier change, both tests will fail. Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20250524041340.4046304-1-yonghong.song@linux.dev [ shung-hsi.yu: contains additional hunks for kernel/bpf/verifier.c that should be part of the previous patch in the series, commit e2d2115e56c4 "bpf: Do not include stack ptr register in precision backtracking bookkeeping", which already incorporated. ] Link: https://lore.kernel.org/all/9b41f9f5-396f-47e0-9a12-46c52087df6c@linux.dev/ Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-06libbpf: Fix possible use-after-free for externsAdin Scannell1-0/+16
[ Upstream commit fa6f092cc0a02d0fcee37e9e8172eda372a03d33 ] The `name` field in `obj->externs` points into the BTF data at initial open time. However, some functions may invalidate this after opening and before loading (e.g. `bpf_map__set_value_size`), which results in pointers into freed memory and undefined behavior. The simplest solution is to simply `strdup` these strings, similar to the `essent_name`, and free them at the same time. In order to test this path, the `global_map_resize` BPF selftest is modified slightly to ensure the presence of an extern, which causes this test to fail prior to the fix. Given there isn't an obvious API or error to test against, I opted to add this to the existing test as an aspect of the resizing feature rather than duplicate the test. Fixes: 9d0a23313b1a ("libbpf: Add capability for resizing datasec maps") Signed-off-by: Adin Scannell <amscanne@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20250625050215.2777374-1-amscanne@meta.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-02selftests/bpf: check program redirect in xdp_cpumap_attachAlexis Lothoré (eBPF Foundation)1-0/+5
commit d124d984c8a2d677e1cea6740a01ccdd0371a38d upstream. xdp_cpumap_attach, in its current form, only checks that an xdp cpumap program can be executed, but not that it performs correctly the cpu redirect as configured by userspace (bpf_prog_test_run_opts will return success even if the redirect program returns an error) Add a check to ensure that the program performs the configured redirect as well. The check is based on a global variable incremented by a chained program executed only if the redirect program properly executes. Signed-off-by: Alexis Lothoré (eBPF Foundation) <alexis.lothore@bootlin.com> Link: https://lore.kernel.org/r/20241009-convert_xdp_tests-v3-3-51cea913710c@bootlin.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-02selftests/bpf: fix bpf_map_redirect call for cpu map testAlexis Lothoré (eBPF Foundation)1-1/+1
commit ac8d16b2d3772934f4cba44cb01bad05b4b2864c upstream. xdp_redir_prog currently redirects packets based on the entry at index 1 in cpu_map, but the corresponding test only manipulates the entry at index 0. This does not really affect the test in its current form since the program is detached before having the opportunity to execute, but it needs to be fixed before being able improve the corresponding test (ie, not only test attach/detach but also the redirect feature) Fix this XDP program by making it redirect packets based on entry 0 in cpu_map instead of entry 1. Signed-off-by: Alexis Lothoré (eBPF Foundation) <alexis.lothore@bootlin.com> Link: https://lore.kernel.org/r/20241009-convert_xdp_tests-v3-1-51cea913710c@bootlin.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-25selftests/bpf: extend changes_pkt_data with cases w/o subprogramsEduard Zingerman2-10/+23
commit 04789af756a4a43e72986185f66f148e65b32fed upstream. Extend changes_pkt_data tests with test cases freplacing the main program that does not have subprograms. Try four combinations when both main program and replacement do and do not change packet data. Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20241212070711.427443-2-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-25selftests/bpf: validate that tail call invalidates packet pointersEduard Zingerman1-0/+28
commit d9706b56e13b7916461ca6b4b731e169ed44ed09 upstream. Add a test case with a tail call done from a global sub-program. Such tails calls should be considered as invalidating packet pointers. Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20241210041100.1898468-9-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-25selftests/bpf: freplace tests for tracking of changes_packet_dataEduard Zingerman2-0/+44
commit 89ff40890d8f12a7d7e93fb602cc27562f3834f0 upstream. Try different combinations of global functions replacement: - replace function that changes packet data with one that doesn't; - replace function that changes packet data with one that does; - replace function that doesn't change packet data with one that does; - replace function that doesn't change packet data with one that doesn't; Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20241210041100.1898468-7-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-25selftests/bpf: test for changing packet data from global functionsEduard Zingerman1-0/+28
commit 3f23ee5590d9605dbde9a5e1d4b97637a4803329 upstream. Check if verifier is aware of packet pointers invalidation done in global functions. Based on a test shared by Nick Zavaritsky in [0]. [0] https://lore.kernel.org/bpf/0498CA22-5779-4767-9C0C-A9515CEA711F@gmail.com/ Suggested-by: Nick Zavaritsky <mejedi@gmail.com> Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20241210041100.1898468-5-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-25selftests/bpf: Fix raw_tp null handling testShung-Hsi Yu1-10/+9
Commit b2fc4b17fc13, backport of upstream commit 838a10bd2ebf ("bpf: Augment raw_tp arguments with PTR_MAYBE_NULL"), was missing the changes to tools/testing/selftests/bpf/progs/raw_tp_null.c, and cause the test to fail with the following error (see link below for the complete log) Error: #205 raw_tp_null libbpf: prog 'test_raw_tp_null': BPF program load failed: Permission denied libbpf: prog 'test_raw_tp_null': -- BEGIN PROG LOAD LOG -- 0: R1=ctx() R10=fp0 ; int BPF_PROG(test_raw_tp_null, struct sk_buff *skb) @ raw_tp_null.c:13 0: (79) r6 = *(u64 *)(r1 +0) func 'bpf_testmod_test_raw_tp_null' arg0 has btf_id 2081 type STRUCT 'sk_buff' 1: R1=ctx() R6_w=trusted_ptr_or_null_sk_buff(id=1) ; struct task_struct *task = bpf_get_current_task_btf(); @ raw_tp_null.c:15 1: (85) call bpf_get_current_task_btf#158 ; R0_w=trusted_ptr_task_struct() ; if (task->pid != tid) @ raw_tp_null.c:17 2: (61) r1 = *(u32 *)(r0 +1416) ; R0_w=trusted_ptr_task_struct() R1_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) 3: (18) r2 = 0xffffa3bb801c6000 ; R2_w=map_value(map=raw_tp_n.bss,ks=4,vs=8) 5: (61) r2 = *(u32 *)(r2 +0) ; R2_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) 6: (5e) if w1 != w2 goto pc+11 ; R1_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R2_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) ; i = i + skb->mark + 1; @ raw_tp_null.c:20 7: (61) r2 = *(u32 *)(r6 +164) R6 invalid mem access 'trusted_ptr_or_null_' processed 7 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0 -- END PROG LOAD LOG -- libbpf: prog 'test_raw_tp_null': failed to load: -13 libbpf: failed to load object 'raw_tp_null' libbpf: failed to load BPF skeleton 'raw_tp_null': -13 test_raw_tp_null:FAIL:raw_tp_null__open_and_load unexpected error: -13 Bring the missing changes in to fix the test failure. Link: https://github.com/shunghsiyu/libbpf/actions/runs/14522396622/job/40766998873 Fixes: b2fc4b17fc13 ("bpf: Augment raw_tp arguments with PTR_MAYBE_NULL") Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-10selftests/bpf: Fix string read in strncmp benchmarkViktor Malik1-1/+4
[ Upstream commit de07b182899227d5fd1ca7a1a7d495ecd453d49c ] The strncmp benchmark uses the bpf_strncmp helper and a hand-written loop to compare two strings. The values of the strings are filled from userspace. One of the strings is non-const (in .bss) while the other is const (in .rodata) since that is the requirement of bpf_strncmp. The problem is that in the hand-written loop, Clang optimizes the reads from the const string to always return 0 which breaks the benchmark. Use barrier_var to prevent the optimization. The effect can be seen on the strncmp-no-helper variant. Before this change: # ./bench strncmp-no-helper Setting up benchmark 'strncmp-no-helper'... Benchmark 'strncmp-no-helper' started. Iter 0 (112.309us): hits 0.000M/s ( 0.000M/prod), drops 0.000M/s, total operations 0.000M/s Iter 1 (-23.238us): hits 0.000M/s ( 0.000M/prod), drops 0.000M/s, total operations 0.000M/s Iter 2 ( 58.994us): hits 0.000M/s ( 0.000M/prod), drops 0.000M/s, total operations 0.000M/s Iter 3 (-30.466us): hits 0.000M/s ( 0.000M/prod), drops 0.000M/s, total operations 0.000M/s Iter 4 ( 29.996us): hits 0.000M/s ( 0.000M/prod), drops 0.000M/s, total operations 0.000M/s Iter 5 ( 16.949us): hits 0.000M/s ( 0.000M/prod), drops 0.000M/s, total operations 0.000M/s Iter 6 (-60.035us): hits 0.000M/s ( 0.000M/prod), drops 0.000M/s, total operations 0.000M/s Summary: hits 0.000 ± 0.000M/s ( 0.000M/prod), drops 0.000 ± 0.000M/s, total operations 0.000 ± 0.000M/s After this change: # ./bench strncmp-no-helper Setting up benchmark 'strncmp-no-helper'... Benchmark 'strncmp-no-helper' started. Iter 0 ( 77.711us): hits 5.534M/s ( 5.534M/prod), drops 0.000M/s, total operations 5.534M/s Iter 1 ( 11.215us): hits 6.006M/s ( 6.006M/prod), drops 0.000M/s, total operations 6.006M/s Iter 2 (-14.253us): hits 5.931M/s ( 5.931M/prod), drops 0.000M/s, total operations 5.931M/s Iter 3 ( 59.087us): hits 6.005M/s ( 6.005M/prod), drops 0.000M/s, total operations 6.005M/s Iter 4 (-21.379us): hits 6.010M/s ( 6.010M/prod), drops 0.000M/s, total operations 6.010M/s Iter 5 (-20.310us): hits 5.861M/s ( 5.861M/prod), drops 0.000M/s, total operations 5.861M/s Iter 6 ( 53.937us): hits 6.004M/s ( 6.004M/prod), drops 0.000M/s, total operations 6.004M/s Summary: hits 5.969 ± 0.061M/s ( 5.969M/prod), drops 0.000 ± 0.000M/s, total operations 5.969 ± 0.061M/s Fixes: 9c42652f8be3 ("selftests/bpf: Add benchmark for bpf_strncmp() helper") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Viktor Malik <vmalik@redhat.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/bpf/20250313122852.1365202-1-vmalik@redhat.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-27selftests/bpf: Add tests for raw_tp null handlingKumar Kartikeya Dwivedi1-0/+32
[ Upstream commit d798ce3f4cab1b0d886b19ec5cc8e6b3d7e35081 ] Ensure that trusted PTR_TO_BTF_ID accesses perform PROBE_MEM handling in raw_tp program. Without the previous fix, this selftest crashes the kernel due to a NULL-pointer dereference. Also ensure that dead code elimination does not kick in for checks on the pointer. Reviewed-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20241104171959.2938862-4-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Stable-dep-of: 5da7e15fb5a1 ("net: Add rx_skb of kfree_skb to raw_tp_null_args[].") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-08selftests/bpf: Add test to verify tailcall and freplace restrictionsLeon Hwang1-2/+3
commit 021611d33e78694f4bd54573093c6fc70a812644 upstream. Add a test case to ensure that attaching a tail callee program with an freplace program fails, and that updating an extended program to a prog_array map is also prohibited. This test is designed to prevent the potential infinite loop issue caused by the combination of tail calls and freplace, ensuring the correct behavior and stability of the system. Additionally, fix the broken tailcalls/tailcall_freplace selftest because an extension prog should not be tailcalled. cd tools/testing/selftests/bpf; ./test_progs -t tailcalls 337/25 tailcalls/tailcall_freplace:OK 337/26 tailcalls/tailcall_bpf2bpf_freplace:OK 337 tailcalls:OK Summary: 1/26 PASSED, 0 SKIPPED, 0 FAILED Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Leon Hwang <leon.hwang@linux.dev> Link: https://lore.kernel.org/r/20241015150207.70264-3-leon.hwang@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> [ Yifei: bpf freplace update is backported to linux-6.12 by commit 987aa730bad3 ("bpf: Prevent tailcall infinite loop caused by freplace"). It will cause selftest #336/25 failed. ] Signed-off-by: Yifei Liu <yifei.l.liu@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-08selftests/bpf: Fix fill_link_info selftest on powerpcSaket Kumar Bhaskar1-3/+10
[ Upstream commit 4d33dc1bc31df80356c49e40dbd3ddff19500bcb ] With CONFIG_KPROBES_ON_FTRACE enabled on powerpc, ftrace_location_range returns ftrace location for bpf_fentry_test1 at offset of 4 bytes from function entry. This is because branch to _mcount function is at offset of 4 bytes in function profile sequence. To fix this, add entry_offset of 4 bytes while verifying the address for kprobe entry address of bpf_fentry_test1 in verify_perf_link_info in selftest, when CONFIG_KPROBES_ON_FTRACE is enabled. Disassemble of bpf_fentry_test1: c000000000e4b080 <bpf_fentry_test1>: c000000000e4b080: a6 02 08 7c mflr r0 c000000000e4b084: b9 e2 22 4b bl c00000000007933c <_mcount> c000000000e4b088: 01 00 63 38 addi r3,r3,1 c000000000e4b08c: b4 07 63 7c extsw r3,r3 c000000000e4b090: 20 00 80 4e blr When CONFIG_PPC_FTRACE_OUT_OF_LINE [1] is enabled, these function profile sequence is moved out of line with an unconditional branch at offset 0. So, the test works without altering the offset for 'CONFIG_KPROBES_ON_FTRACE && CONFIG_PPC_FTRACE_OUT_OF_LINE' case. Disassemble of bpf_fentry_test1: c000000000f95190 <bpf_fentry_test1>: c000000000f95190: 00 00 00 60 nop c000000000f95194: 01 00 63 38 addi r3,r3,1 c000000000f95198: b4 07 63 7c extsw r3,r3 c000000000f9519c: 20 00 80 4e blr [1] https://lore.kernel.org/all/20241030070850.1361304-13-hbathini@linux.ibm.com/ Fixes: 23cf7aa539dc ("selftests/bpf: Add selftest for fill_link_info") Signed-off-by: Saket Kumar Bhaskar <skb99@linux.ibm.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241209065720.234344-1-skb99@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-09bpf: consider that tail calls invalidate packet pointersEduard Zingerman1-0/+2
[ Upstream commit 1a4607ffba35bf2a630aab299e34dd3f6e658d70 ] Tail-called programs could execute any of the helpers that invalidate packet pointers. Hence, conservatively assume that each tail call invalidates packet pointers. Making the change in bpf_helper_changes_pkt_data() automatically makes use of check_cfg() logic that computes 'changes_pkt_data' effect for global sub-programs, such that the following program could be rejected: int tail_call(struct __sk_buff *sk) { bpf_tail_call_static(sk, &jmp_table, 0); return 0; } SEC("tc") int not_safe(struct __sk_buff *sk) { int *p = (void *)(long)sk->data; ... make p valid ... tail_call(sk); *p = 42; /* this is unsafe */ ... } The tc_bpf2bpf.c:subprog_tc() needs change: mark it as a function that can invalidate packet pointers. Otherwise, it can't be freplaced with tailcall_freplace.c:entry_freplace() that does a tail call. Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20241210041100.1898468-8-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-02bpf: Zero index arg error string for dynptr and iterKumar Kartikeya Dwivedi5-23/+23
[ Upstream commit bd74e238ae6944b462f57ce8752440a011ba4530 ] Andrii spotted that process_dynptr_func's rejection of incorrect argument register type will print an error string where argument numbers are not zero-indexed, unlike elsewhere in the verifier. Fix this by subtracting 1 from regno. The same scenario exists for iterator messages. Fix selftest error strings that match on the exact argument number while we're at it to ensure clean bisection. Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20241203002235.3776418-1-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-19bpf: Check size for BTF-based ctx access of pointer membersKumar Kartikeya Dwivedi2-4/+4
commit 659b9ba7cb2d7adb64618b87ddfaa528a143766e upstream. Robert Morris reported the following program type which passes the verifier in [0]: SEC("struct_ops/bpf_cubic_init") void BPF_PROG(bpf_cubic_init, struct sock *sk) { asm volatile("r2 = *(u16*)(r1 + 0)"); // verifier should demand u64 asm volatile("*(u32 *)(r2 +1504) = 0"); // 1280 in some configs } The second line may or may not work, but the first instruction shouldn't pass, as it's a narrow load into the context structure of the struct ops callback. The code falls back to btf_ctx_access to ensure correctness and obtaining the types of pointers. Ensure that the size of the access is correctly checked to be 8 bytes, otherwise the verifier thinks the narrow load obtained a trusted BTF pointer and will permit loads/stores as it sees fit. Perform the check on size after we've verified that the load is for a pointer field, as for scalar values narrow loads are fine. Access to structs passed as arguments to a BPF program are also treated as scalars, therefore no adjustment is needed in their case. Existing verifier selftests are broken by this change, but because they were incorrect. Verifier tests for d_path were performing narrow load into context to obtain path pointer, had this program actually run it would cause a crash. The same holds for verifier_btf_ctx_access tests. [0]: https://lore.kernel.org/bpf/51338.1732985814@localhost Fixes: 9e15db66136a ("bpf: Implement accurate raw_tp context access via BTF") Reported-by: Robert Morris <rtm@mit.edu> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20241212092050.3204165-2-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-19bpf: Revert "bpf: Mark raw_tp arguments with PTR_MAYBE_NULL"Kumar Kartikeya Dwivedi1-5/+1
commit c00d738e1673ab801e1577e4e3c780ccf88b1a5b upstream. This patch reverts commit cb4158ce8ec8 ("bpf: Mark raw_tp arguments with PTR_MAYBE_NULL"). The patch was well-intended and meant to be as a stop-gap fixing branch prediction when the pointer may actually be NULL at runtime. Eventually, it was supposed to be replaced by an automated script or compiler pass detecting possibly NULL arguments and marking them accordingly. However, it caused two main issues observed for production programs and failed to preserve backwards compatibility. First, programs relied on the verifier not exploring == NULL branch when pointer is not NULL, thus they started failing with a 'dereference of scalar' error. Next, allowing raw_tp arguments to be modified surfaced the warning in the verifier that warns against reg->off when PTR_MAYBE_NULL is set. More information, context, and discusson on both problems is available in [0]. Overall, this approach had several shortcomings, and the fixes would further complicate the verifier's logic, and the entire masking scheme would have to be removed eventually anyway. Hence, revert the patch in preparation of a better fix avoiding these issues to replace this commit. [0]: https://lore.kernel.org/bpf/20241206161053.809580-1-memxor@gmail.com Reported-by: Manu Bretelle <chantra@meta.com> Fixes: cb4158ce8ec8 ("bpf: Mark raw_tp arguments with PTR_MAYBE_NULL") Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20241213221929.3495062-2-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-14bpf: Ensure reg is PTR_TO_STACK in process_iter_argTao Lyu1-2/+2
[ Upstream commit 12659d28615d606b36e382f4de2dd05550d202af ] Currently, KF_ARG_PTR_TO_ITER handling missed checking the reg->type and ensuring it is PTR_TO_STACK. Instead of enforcing this in the caller of process_iter_arg, move the check into it instead so that all callers will gain the check by default. This is similar to process_dynptr_func. An existing selftest in verifier_bits_iter.c fails due to this change, but it's because it was passing a NULL pointer into iter_next helper and getting an error further down the checks, but probably meant to pass an uninitialized iterator on the stack (as is done in the subsequent test below it). We will gain coverage for non-PTR_TO_STACK arguments in later patches hence just change the declaration to zero-ed stack object. Fixes: 06accc8779c1 ("bpf: add support for open-coded iterator loops") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Tao Lyu <tao.lyu@epfl.ch> [ Kartikeya: move check into process_iter_arg, rewrite commit log ] Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20241203000238.3602922-2-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-05bpf: Mark raw_tp arguments with PTR_MAYBE_NULLKumar Kartikeya Dwivedi1-1/+5
[ Upstream commit cb4158ce8ec8a5bb528cc1693356a5eb8058094d ] Arguments to a raw tracepoint are tagged as trusted, which carries the semantics that the pointer will be non-NULL. However, in certain cases, a raw tracepoint argument may end up being NULL. More context about this issue is available in [0]. Thus, there is a discrepancy between the reality, that raw_tp arguments can actually be NULL, and the verifier's knowledge, that they are never NULL, causing explicit NULL checks to be deleted, and accesses to such pointers potentially crashing the kernel. To fix this, mark raw_tp arguments as PTR_MAYBE_NULL, and then special case the dereference and pointer arithmetic to permit it, and allow passing them into helpers/kfuncs; these exceptions are made for raw_tp programs only. Ensure that we don't do this when ref_obj_id > 0, as in that case this is an acquired object and doesn't need such adjustment. The reason we do mask_raw_tp_trusted_reg logic is because other will recheck in places whether the register is a trusted_reg, and then consider our register as untrusted when detecting the presence of the PTR_MAYBE_NULL flag. To allow safe dereference, we enable PROBE_MEM marking when we see loads into trusted pointers with PTR_MAYBE_NULL. While trusted raw_tp arguments can also be passed into helpers or kfuncs where such broken assumption may cause issues, a future patch set will tackle their case separately, as PTR_TO_BTF_ID (without PTR_TRUSTED) can already be passed into helpers and causes similar problems. Thus, they are left alone for now. It is possible that these checks also permit passing non-raw_tp args that are trusted PTR_TO_BTF_ID with null marking. In such a case, allowing dereference when pointer is NULL expands allowed behavior, so won't regress existing programs, and the case of passing these into helpers is the same as above and will be dealt with later. Also update the failure case in tp_btf_nullable selftest to capture the new behavior, as the verifier will no longer cause an error when directly dereference a raw tracepoint argument marked as __nullable. [0]: https://lore.kernel.org/bpf/ZrCZS6nisraEqehw@jlelli-thinkpadt14gen4.remote.csb Reviewed-by: Jiri Olsa <jolsa@kernel.org> Reported-by: Juri Lelli <juri.lelli@redhat.com> Tested-by: Juri Lelli <juri.lelli@redhat.com> Fixes: 3f00c5239344 ("bpf: Allow trusted pointers to be passed to KF_TRUSTED_ARGS kfuncs") Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20241104171959.2938862-2-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-05selftests/bpf: fix test_spin_lock_fail.c's global vars usageAndrii Nakryiko1-2/+2
[ Upstream commit 1b2bfc29695d273492c3dd8512775261f3272686 ] Global variables of special types (like `struct bpf_spin_lock`) make underlying ARRAY maps non-mmapable. To make this work with libbpf's mmaping logic, application is expected to declare such special variables as static, so libbpf doesn't even attempt to mmap() such ARRAYs. test_spin_lock_fail.c didn't follow this rule, but given it relied on this test to trigger failures, this went unnoticed, as we never got to the step of mmap()'ing these ARRAY maps. It is fragile and relies on specific sequence of libbpf steps, which are an internal implementation details. Fix the test by marking lockA and lockB as static. Fixes: c48748aea4f8 ("selftests/bpf: Add failure test cases for spin lock pairing") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20241023043908.3834423-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-06selftests/bpf: Use -4095 as the bad address for bits iteratorHou Tao1-4/+28
As reported by Byeonguk, the bad_words test in verifier_bits_iter.c occasionally fails on s390 host. Quoting Ilya's explanation: s390 kernel runs in a completely separate address space, there is no user/kernel split at TASK_SIZE. The same address may be valid in both the kernel and the user address spaces, there is no way to tell by looking at it. The config option related to this property is ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE. Also, unfortunately, 0 is a valid address in the s390 kernel address space. Fix the issue by using -4095 as the bad address for bits iterator, as suggested by Ilya. Verify that bpf_iter_bits_new() returns -EINVAL for NULL address and -EFAULT for bad address. Fixes: ebafc1e535db ("selftests/bpf: Add three test cases for bits_iter") Reported-by: Byeonguk Jeong <jungbu2855@gmail.com> Closes: https://lore.kernel.org/bpf/ZycSXwjH4UTvx-Cn@ub22/ Signed-off-by: Hou Tao <houtao1@huawei.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Link: https://lore.kernel.org/r/20241105043057.3371482-1-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-30selftests/bpf: Add three test cases for bits_iterHou Tao1-3/+58
Add more test cases for bits iterator: (1) huge word test Verify the multiplication overflow of nr_bits in bits_iter. Without the overflow check, when nr_words is 67108865, nr_bits becomes 64, causing bpf_probe_read_kernel_common() to corrupt the stack. (2) max word test Verify correct handling of maximum nr_words value (511). (3) bad word test Verify early termination of bits iteration when bits iterator initialization fails. Also rename bits_nomem to bits_too_big to better reflect its purpose. Signed-off-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20241030100516.3633640-6-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-30bpf: disallow 40-bytes extra stack for bpf_fastcall patternsEduard Zingerman1-55/+0
Hou Tao reported an issue with bpf_fastcall patterns allowing extra stack space above MAX_BPF_STACK limit. This extra stack allowance is not integrated properly with the following verifier parts: - backtracking logic still assumes that stack can't exceed MAX_BPF_STACK; - bpf_verifier_env->scratched_stack_slots assumes only 64 slots are available. Here is an example of an issue with precision tracking (note stack slot -8 tracked as precise instead of -520): 0: (b7) r1 = 42 ; R1_w=42 1: (b7) r2 = 42 ; R2_w=42 2: (7b) *(u64 *)(r10 -512) = r1 ; R1_w=42 R10=fp0 fp-512_w=42 3: (7b) *(u64 *)(r10 -520) = r2 ; R2_w=42 R10=fp0 fp-520_w=42 4: (85) call bpf_get_smp_processor_id#8 ; R0_w=scalar(...) 5: (79) r2 = *(u64 *)(r10 -520) ; R2_w=42 R10=fp0 fp-520_w=42 6: (79) r1 = *(u64 *)(r10 -512) ; R1_w=42 R10=fp0 fp-512_w=42 7: (bf) r3 = r10 ; R3_w=fp0 R10=fp0 8: (0f) r3 += r2 mark_precise: frame0: last_idx 8 first_idx 0 subseq_idx -1 mark_precise: frame0: regs=r2 stack= before 7: (bf) r3 = r10 mark_precise: frame0: regs=r2 stack= before 6: (79) r1 = *(u64 *)(r10 -512) mark_precise: frame0: regs=r2 stack= before 5: (79) r2 = *(u64 *)(r10 -520) mark_precise: frame0: regs= stack=-8 before 4: (85) call bpf_get_smp_processor_id#8 mark_precise: frame0: regs= stack=-8 before 3: (7b) *(u64 *)(r10 -520) = r2 mark_precise: frame0: regs=r2 stack= before 2: (7b) *(u64 *)(r10 -512) = r1 mark_precise: frame0: regs=r2 stack= before 1: (b7) r2 = 42 9: R2_w=42 R3_w=fp42 9: (95) exit This patch disables the additional allowance for the moment. Also, two test cases are removed: - bpf_fastcall_max_stack_ok: it fails w/o additional stack allowance; - bpf_fastcall_max_stack_fail: this test is no longer necessary, stack size follows regular rules, pattern invalidation is checked by other test cases. Reported-by: Hou Tao <houtao@huaweicloud.com> Closes: https://lore.kernel.org/bpf/20241023022752.172005-1-houtao@huaweicloud.com/ Fixes: 5b5f51bff1b6 ("bpf: no_caller_saved_registers attribute for helper calls") Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Tested-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20241029193911.1575719-1-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-29selftests/bpf: Test with a very short loopEduard Zingerman1-0/+23
The test added is a simplified reproducer from syzbot report [1]. If verifier does not insert checkpoint somewhere inside the loop, verification of the program would take a very long time. This would happen because mark_chain_precision() for register r7 would constantly trace jump history of the loop back, processing many iterations for each mark_chain_precision() call. [1] https://lore.kernel.org/bpf/670429f6.050a0220.49194.0517.GAE@google.com/ Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20241029172641.1042523-2-eddyz87@gmail.com
2024-10-23selftests/bpf: Add test for passing in uninit mtu_lenDaniel Borkmann1-0/+18
Add a small test to pass an uninitialized mtu_len to the bpf_check_mtu() helper to probe whether the verifier rejects it under !CAP_PERFMON. # ./vmtest.sh -- ./test_progs -t verifier_mtu [...] ./test_progs -t verifier_mtu [ 1.414712] tsc: Refined TSC clocksource calibration: 3407.993 MHz [ 1.415327] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x311fcd52370, max_idle_ns: 440795242006 ns [ 1.416463] clocksource: Switched to clocksource tsc [ 1.429842] bpf_testmod: loading out-of-tree module taints kernel. [ 1.430283] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel #510/1 verifier_mtu/uninit/mtu: write rejected:OK #510 verifier_mtu:OK Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20241021152809.33343-5-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-23selftests/bpf: Add test for writes to .rodataDaniel Borkmann1-1/+30
Add a small test to write a (verification-time) fixed vs unknown but bounded-sized buffer into .rodata BPF map and assert that both get rejected. # ./vmtest.sh -- ./test_progs -t verifier_const [...] ./test_progs -t verifier_const [ 1.418717] tsc: Refined TSC clocksource calibration: 3407.994 MHz [ 1.419113] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x311fcde90a1, max_idle_ns: 440795222066 ns [ 1.419972] clocksource: Switched to clocksource tsc [ 1.449596] bpf_testmod: loading out-of-tree module taints kernel. [ 1.449958] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel #475/1 verifier_const/rodata/strtol: write rejected:OK #475/2 verifier_const/bss/strtol: write accepted:OK #475/3 verifier_const/data/strtol: write accepted:OK #475/4 verifier_const/rodata/mtu: write rejected:OK #475/5 verifier_const/bss/mtu: write accepted:OK #475/6 verifier_const/data/mtu: write accepted:OK #475/7 verifier_const/rodata/mark: write with unknown reg rejected:OK #475/8 verifier_const/rodata/mark: write with unknown reg rejected:OK #475 verifier_const:OK #476/1 verifier_const_or/constant register |= constant should keep constant type:OK #476/2 verifier_const_or/constant register |= constant should not bypass stack boundary checks:OK #476/3 verifier_const_or/constant register |= constant register should keep constant type:OK #476/4 verifier_const_or/constant register |= constant register should not bypass stack boundary checks:OK #476 verifier_const_or:OK Summary: 2/12 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20241021152809.33343-4-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-19Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfLinus Torvalds8-3/+288
Pull bpf fixes from Daniel Borkmann: - Fix BPF verifier to not affect subreg_def marks in its range propagation (Eduard Zingerman) - Fix a truncation bug in the BPF verifier's handling of coerce_reg_to_size_sx (Dimitar Kanaliev) - Fix the BPF verifier's delta propagation between linked registers under 32-bit addition (Daniel Borkmann) - Fix a NULL pointer dereference in BPF devmap due to missing rxq information (Florian Kauer) - Fix a memory leak in bpf_core_apply (Jiri Olsa) - Fix an UBSAN-reported array-index-out-of-bounds in BTF parsing for arrays of nested structs (Hou Tao) - Fix build ID fetching where memory areas backing the file were created with memfd_secret (Andrii Nakryiko) - Fix BPF task iterator tid filtering which was incorrectly using pid instead of tid (Jordan Rome) - Several fixes for BPF sockmap and BPF sockhash redirection in combination with vsocks (Michal Luczaj) - Fix riscv BPF JIT and make BPF_CMPXCHG fully ordered (Andrea Parri) - Fix riscv BPF JIT under CONFIG_CFI_CLANG to prevent the possibility of an infinite BPF tailcall (Pu Lehui) - Fix a build warning from resolve_btfids that bpf_lsm_key_free cannot be resolved (Thomas Weißschuh) - Fix a bug in kfunc BTF caching for modules where the wrong BTF object was returned (Toke Høiland-Jørgensen) - Fix a BPF selftest compilation error in cgroup-related tests with musl libc (Tony Ambardar) - Several fixes to BPF link info dumps to fill missing fields (Tyrone Wu) - Add BPF selftests for kfuncs from multiple modules, checking that the correct kfuncs are called (Simon Sundberg) - Ensure that internal and user-facing bpf_redirect flags don't overlap (Toke Høiland-Jørgensen) - Switch to use kvzmalloc to allocate BPF verifier environment (Rik van Riel) - Use raw_spinlock_t in BPF ringbuf to fix a sleep in atomic splat under RT (Wander Lairson Costa) * tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: (38 commits) lib/buildid: Handle memfd_secret() files in build_id_parse() selftests/bpf: Add test case for delta propagation bpf: Fix print_reg_state's constant scalar dump bpf: Fix incorrect delta propagation between linked registers bpf: Properly test iter/task tid filtering bpf: Fix iter/task tid filtering riscv, bpf: Make BPF_CMPXCHG fully ordered bpf, vsock: Drop static vsock_bpf_prot initialization vsock: Update msg_count on read_skb() vsock: Update rx_bytes on read_skb() bpf, sockmap: SK_DROP on attempted redirects of unsupported af_vsock selftests/bpf: Add asserts for netfilter link info bpf: Fix link info netfilter flags to populate defrag flag selftests/bpf: Add test for sign extension in coerce_subreg_to_size_sx() selftests/bpf: Add test for truncation after sign extension in coerce_reg_to_size_sx() bpf: Fix truncation bug in coerce_reg_to_size_sx() selftests/bpf: Assert link info uprobe_multi count & path_size if unset bpf: Fix unpopulated path_size when uprobe_multi fields unset selftests/bpf: Fix cross-compiling urandom_read selftests/bpf: Add test for kfunc module order ...
2024-10-17selftests/bpf: Add test case for delta propagationDaniel Borkmann1-0/+34
Add a small BPF verifier test case to ensure that alu32 additions to registers are not subject to linked scalar delta tracking. # ./vmtest.sh -- ./test_progs -t verifier_linked_scalars [...] ./test_progs -t verifier_linked_scalars [ 1.413138] tsc: Refined TSC clocksource calibration: 3407.993 MHz [ 1.413524] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x311fcd52370, max_idle_ns: 440795242006 ns [ 1.414223] clocksource: Switched to clocksource tsc [ 1.419640] bpf_testmod: loading out-of-tree module taints kernel. [ 1.420025] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel #500/1 verifier_linked_scalars/scalars: find linked scalars:OK #500 verifier_linked_scalars:OK Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED [ 1.590858] ACPI: PM: Preparing to enter system sleep state S5 [ 1.591402] reboot: Power down [...] Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/bpf/20241016134913.32249-3-daniel@iogearbox.net
2024-10-15selftests/bpf: Add test for sign extension in coerce_subreg_to_size_sx()Dimitar Kanaliev1-0/+20
Add a test for unsigned ranges after signed extension instruction. This case isn't currently covered by existing tests in verifier_movsx.c. Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Dimitar Kanaliev <dimitar.kanaliev@siteground.com> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20241014121155.92887-4-dimitar.kanaliev@siteground.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-15selftests/bpf: Add test for truncation after sign extension in ↵Dimitar Kanaliev1-0/+20
coerce_reg_to_size_sx() Add test that checks whether unsigned ranges deduced by the verifier for sign extension instruction is correct. Without previous patch that fixes truncation in coerce_reg_to_size_sx() this test fails. Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Dimitar Kanaliev <dimitar.kanaliev@siteground.com> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20241014121155.92887-3-dimitar.kanaliev@siteground.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-10selftests/bpf: Add test for kfunc module orderSimon Sundberg1-0/+30
Add a test case for kfuncs from multiple external modules, checking that the correct kfuncs are called regardless of which order they're called in. Specifically, check that calling the kfuncs in an order different from the one the modules' BTF are loaded in works. Signed-off-by: Simon Sundberg <simon.sundberg@kau.se> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/r/20241010-fix-kfunc-btf-caching-for-modules-v2-3-745af6c1af98@redhat.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-10selftests/bpf: Add more test case for field flatteningHou Tao3-2/+116
Add three success test cases to test the flattening of array of nested struct. For these three tests, the number of special fields in map is BTF_FIELDS_MAX, but the array is defined in structs with different nested level. Add one failure test case for the flattening as well. In the test case, the number of special fields in map is BTF_FIELDS_MAX + 1. It will make btf_parse_fields() in map_create() return -E2BIG, the creation of map will succeed, but the load of program will fail because the btf_record is invalid for the map. Signed-off-by: Hou Tao <houtao1@huawei.com> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20241008071114.3718177-3-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-03move asm/unaligned.h to linux/unaligned.hAl Viro1-1/+1
asm/unaligned.h is always an include of asm-generic/unaligned.h; might as well move that thing to linux/unaligned.h and include that - there's nothing arch-specific in that header. auto-generated by the following: for i in `git grep -l -w asm/unaligned.h`; do sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i done for i in `git grep -l -w asm-generic/unaligned.h`; do sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i done git mv include/asm-generic/unaligned.h include/linux/unaligned.h git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
2024-10-02bpf: selftests: send packet to devmap redirect XDPFlorian Kauer1-1/+1
The current xdp_devmap_attach test attaches a program that redirects to another program via devmap. It is, however, never executed, so do that to catch any bugs that might occur during execution. Also, execute the same for a veth pair so that we also cover the non-generic path. Warning: Running this without the bugfix in this series will likely crash your system. Signed-off-by: Florian Kauer <florian.kauer@linutronix.de> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/r/20240911-devel-koalo-fix-ingress-ifindex-v4-2-5c643ae10258@linutronix.de Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-10-01selftests/bpf: Verify that sync_linked_regs preserves subreg_defEduard Zingerman1-0/+67
This test was added because of a bug in verifier.c:sync_linked_regs(), upon range propagation it destroyed subreg_def marks for registers. The test is written in a way to return an upper half of a register that is affected by range propagation and must have it's subreg_def preserved. This gives a return value of 0 and leads to undefined return value if subreg_def mark is not preserved. Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20240924210844.1758441-2-eddyz87@gmail.com
2024-09-21Merge tag 'bpf-next-6.12' of ↵Linus Torvalds71-227/+3975
git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Pull bpf updates from Alexei Starovoitov: - Introduce '__attribute__((bpf_fastcall))' for helpers and kfuncs with corresponding support in LLVM. It is similar to existing 'no_caller_saved_registers' attribute in GCC/LLVM with a provision for backward compatibility. It allows compilers generate more efficient BPF code assuming the verifier or JITs will inline or partially inline a helper/kfunc with such attribute. bpf_cast_to_kern_ctx, bpf_rdonly_cast, bpf_get_smp_processor_id are the first set of such helpers. - Harden and extend ELF build ID parsing logic. When called from sleepable context the relevants parts of ELF file will be read to find and fetch .note.gnu.build-id information. Also harden the logic to avoid TOCTOU, overflow, out-of-bounds problems. - Improvements and fixes for sched-ext: - Allow passing BPF iterators as kfunc arguments - Make the pointer returned from iter_next method trusted - Fix x86 JIT convergence issue due to growing/shrinking conditional jumps in variable length encoding - BPF_LSM related: - Introduce few VFS kfuncs and consolidate them in fs/bpf_fs_kfuncs.c - Enforce correct range of return values from certain LSM hooks - Disallow attaching to other LSM hooks - Prerequisite work for upcoming Qdisc in BPF: - Allow kptrs in program provided structs - Support for gen_epilogue in verifier_ops - Important fixes: - Fix uprobe multi pid filter check - Fix bpf_strtol and bpf_strtoul helpers - Track equal scalars history on per-instruction level - Fix tailcall hierarchy on x86 and arm64 - Fix signed division overflow to prevent INT_MIN/-1 trap on x86 - Fix get kernel stack in BPF progs attached to tracepoint:syscall - Selftests: - Add uprobe bench/stress tool - Generate file dependencies to drastically improve re-build time - Match JIT-ed and BPF asm with __xlated/__jited keywords - Convert older tests to test_progs framework - Add support for RISC-V - Few fixes when BPF programs are compiled with GCC-BPF backend (support for GCC-BPF in BPF CI is ongoing in parallel) - Add traffic monitor - Enable cross compile and musl libc * tag 'bpf-next-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (260 commits) btf: require pahole 1.21+ for DEBUG_INFO_BTF with default DWARF version btf: move pahole check in scripts/link-vmlinux.sh to lib/Kconfig.debug btf: remove redundant CONFIG_BPF test in scripts/link-vmlinux.sh bpf: Call the missed kfree() when there is no special field in btf bpf: Call the missed btf_record_free() when map creation fails selftests/bpf: Add a test case to write mtu result into .rodata selftests/bpf: Add a test case to write strtol result into .rodata selftests/bpf: Rename ARG_PTR_TO_LONG test description selftests/bpf: Fix ARG_PTR_TO_LONG {half-,}uninitialized test bpf: Zero former ARG_PTR_TO_{LONG,INT} args in case of error bpf: Improve check_raw_mode_ok test for MEM_UNINIT-tagged types bpf: Fix helper writes to read-only maps bpf: Remove truncation test in bpf_strtol and bpf_strtoul helpers bpf: Fix bpf_strtol and bpf_strtoul helpers for 32bit selftests/bpf: Add tests for sdiv/smod overflow cases bpf: Fix a sdiv overflow issue libbpf: Add bpf_object__token_fd accessor docs/bpf: Add missing BPF program types to docs docs/bpf: Add constant values for linkages bpf: Use fake pt_regs when doing bpf syscall tracepoint tracing ...
2024-09-13selftests/bpf: Add a test case to write mtu result into .rodataDaniel Borkmann1-3/+30
Add a test which attempts to call bpf_check_mtu() and writes the MTU into .rodata section of the BPF program, and for comparison this adds test cases also for .bss and .data section again. The bpf_check_mtu() is a bit more special in that the passed mtu argument is read and written by the helper (instead of just written to). Assert that writes into .rodata remain rejected by the verifier. # ./vmtest.sh -- ./test_progs -t verifier_const [...] ./test_progs -t verifier_const [ 1.657367] bpf_testmod: loading out-of-tree module taints kernel. [ 1.657773] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel #473/1 verifier_const/rodata/strtol: write rejected:OK #473/2 verifier_const/bss/strtol: write accepted:OK #473/3 verifier_const/data/strtol: write accepted:OK #473/4 verifier_const/rodata/mtu: write rejected:OK #473/5 verifier_const/bss/mtu: write accepted:OK #473/6 verifier_const/data/mtu: write accepted:OK #473 verifier_const:OK [...] Summary: 2/10 PASSED, 0 SKIPPED, 0 FAILED For comparison, without the MEM_UNINIT on bpf_check_mtu's proto: # ./vmtest.sh -- ./test_progs -t verifier_const [...] #473/3 verifier_const/data/strtol: write accepted:OK run_subtest:PASS:obj_open_mem 0 nsec run_subtest:FAIL:unexpected_load_success unexpected success: 0 #473/4 verifier_const/rodata/mtu: write rejected:FAIL #473/5 verifier_const/bss/mtu: write accepted:OK #473/6 verifier_const/data/mtu: write accepted:OK #473 verifier_const:FAIL [...] Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/r/20240913191754.13290-9-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-13selftests/bpf: Add a test case to write strtol result into .rodataDaniel Borkmann1-0/+42
Add a test case which attempts to write into .rodata section of the BPF program, and for comparison this adds test cases also for .bss and .data section. Before fix: # ./vmtest.sh -- ./test_progs -t verifier_const [...] ./test_progs -t verifier_const tester_init:PASS:tester_log_buf 0 nsec process_subtest:PASS:obj_open_mem 0 nsec process_subtest:PASS:specs_alloc 0 nsec run_subtest:PASS:obj_open_mem 0 nsec run_subtest:FAIL:unexpected_load_success unexpected success: 0 #465/1 verifier_const/rodata: write rejected:FAIL #465/2 verifier_const/bss: write accepted:OK #465/3 verifier_const/data: write accepted:OK #465 verifier_const:FAIL [...] After fix: # ./vmtest.sh -- ./test_progs -t verifier_const [...] ./test_progs -t verifier_const #465/1 verifier_const/rodata: write rejected:OK #465/2 verifier_const/bss: write accepted:OK #465/3 verifier_const/data: write accepted:OK #465 verifier_const:OK [...] Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20240913191754.13290-8-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-13selftests/bpf: Rename ARG_PTR_TO_LONG test descriptionDaniel Borkmann1-5/+5
Given we got rid of ARG_PTR_TO_LONG, change the test case description to avoid potential confusion: # ./vmtest.sh -- ./test_progs -t verifier_int_ptr [...] ./test_progs -t verifier_int_ptr [ 1.610563] bpf_testmod: loading out-of-tree module taints kernel. [ 1.611049] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel #489/1 verifier_int_ptr/arg pointer to long uninitialized:OK #489/2 verifier_int_ptr/arg pointer to long half-uninitialized:OK #489/3 verifier_int_ptr/arg pointer to long misaligned:OK #489/4 verifier_int_ptr/arg pointer to long size < sizeof(long):OK #489/5 verifier_int_ptr/arg pointer to long initialized:OK #489 verifier_int_ptr:OK Summary: 1/5 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/r/20240913191754.13290-7-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-13selftests/bpf: Fix ARG_PTR_TO_LONG {half-,}uninitialized testDaniel Borkmann1-4/+1
The assumption of 'in privileged mode reads from uninitialized stack locations are permitted' is not quite correct since the verifier was probing for read access rather than write access. Both tests need to be annotated as __success for privileged and unprivileged. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20240913191754.13290-6-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-13selftests/bpf: Add tests for sdiv/smod overflow casesYonghong Song1-0/+439
Subtests are added to exercise the patched code which handles - LLONG_MIN/-1 - INT_MIN/-1 - LLONG_MIN%-1 - INT_MIN%-1 where -1 could be an immediate or in a register. Without the previous patch, all these cases will crash the kernel on x86_64 platform. Additional tests are added to use small values (e.g. -5/-1, 5%-1, etc.) in order to exercise the additional logic with patched insns. Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20240913150332.1188102-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-11selftests/bpf: Fix arena_atomics failure due to llvm changeYonghong Song1-1/+31
llvm change [1] made a change such that __sync_fetch_and_{and,or,xor}() will generate atomic_fetch_*() insns even if the return value is not used. This is a deliberate choice to make sure barrier semantics are preserved from source code to asm insn. But the change in [1] caused arena_atomics selftest failure. test_arena_atomics:PASS:arena atomics skeleton open 0 nsec libbpf: prog 'and': BPF program load failed: Permission denied libbpf: prog 'and': -- BEGIN PROG LOAD LOG -- arg#0 reference type('UNKNOWN ') size cannot be determined: -22 0: R1=ctx() R10=fp0 ; if (pid != (bpf_get_current_pid_tgid() >> 32)) @ arena_atomics.c:87 0: (18) r1 = 0xffffc90000064000 ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4) 2: (61) r6 = *(u32 *)(r1 +0) ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4) R6_w=scalar(smin=0,smax=umax=0xffffffff,v ar_off=(0x0; 0xffffffff)) 3: (85) call bpf_get_current_pid_tgid#14 ; R0_w=scalar() 4: (77) r0 >>= 32 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) 5: (5d) if r0 != r6 goto pc+11 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R6_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0x) ; __sync_fetch_and_and(&and64_value, 0x011ull << 32); @ arena_atomics.c:91 6: (18) r1 = 0x100000000060 ; R1_w=scalar() 8: (bf) r1 = addr_space_cast(r1, 0, 1) ; R1_w=arena 9: (18) r2 = 0x1100000000 ; R2_w=0x1100000000 11: (db) r2 = atomic64_fetch_and((u64 *)(r1 +0), r2) BPF_ATOMIC stores into R1 arena is not allowed processed 9 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0 -- END PROG LOAD LOG -- libbpf: prog 'and': failed to load: -13 libbpf: failed to load object 'arena_atomics' libbpf: failed to load BPF skeleton 'arena_atomics': -13 test_arena_atomics:FAIL:arena atomics skeleton load unexpected error: -13 (errno 13) #3 arena_atomics:FAIL The reason of the failure is due to [2] where atomic{64,}_fetch_{and,or,xor}() are not allowed by arena addresses. Version 2 of the patch fixed the issue by using inline asm ([3]). But further discussion suggested to find a way from source to generate locked insn which is more user friendly. So in not-merged llvm patch ([4]), if relax memory ordering is used and the return value is not used, locked insn could be generated. So with llvm patch [4] to compile the bpf selftest, the following code __c11_atomic_fetch_and(&and64_value, 0x011ull << 32, memory_order_relaxed); is able to generate locked insn, hence fixing the selftest failure. [1] https://github.com/llvm/llvm-project/pull/106494 [2] d503a04f8bc0 ("bpf: Add support for certain atomics in bpf_arena to x86 JIT") [3] https://lore.kernel.org/bpf/20240803025928.4184433-1-yonghong.song@linux.dev/ [4] https://github.com/llvm/llvm-project/pull/107343 Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20240909223431.1666305-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-11selftests/bpf: add build ID testsAndrii Nakryiko1-0/+31
Add a new set of tests validating behavior of capturing stack traces with build ID. We extend uprobe_multi target binary with ability to trigger uprobe (so that we can capture stack traces from it), but also we allow to force build ID data to be either resident or non-resident in memory (see also a comment about quirks of MADV_PAGEOUT). That way we can validate that in non-sleepable context we won't get build ID (as expected), but with sleepable uprobes we will get that build ID regardless of it being physically present in memory. Also, we add a small add-on linker script which reorders .note.gnu.build-id section and puts it after (big) .text section, putting build ID data outside of the very first page of ELF file. This will test all the relaxations we did in build ID parsing logic in kernel thanks to freader abstraction. Reviewed-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20240829174232.3133883-11-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-11selftests/bpf: Expand skb dynptr selftests for tp_btfPhilo Lu2-0/+48
Add 3 test cases for skb dynptr used in tp_btf: - test_dynptr_skb_tp_btf: use skb dynptr in tp_btf and make sure it is read-only. - skb_invalid_ctx_fentry/skb_invalid_ctx_fexit: bpf_dynptr_from_skb should fail in fentry/fexit. In test_dynptr_skb_tp_btf, to trigger the tracepoint in kfree_skb, test_pkt_access is used for its test_run, as in kfree_skb.c. Because the test process is different from others, a new setup type is defined, i.e., SETUP_SKB_PROG_TP. The result is like: $ ./test_progs -t 'dynptr/test_dynptr_skb_tp_btf' #84/14 dynptr/test_dynptr_skb_tp_btf:OK #84 dynptr:OK #127 kfunc_dynptr_param:OK Summary: 2/1 PASSED, 0 SKIPPED, 0 FAILED $ ./test_progs -t 'dynptr/skb_invalid_ctx_f' #84/85 dynptr/skb_invalid_ctx_fentry:OK #84/86 dynptr/skb_invalid_ctx_fexit:OK #84 dynptr:OK #127 kfunc_dynptr_param:OK Summary: 2/2 PASSED, 0 SKIPPED, 0 FAILED Also fix two coding style nits (change spaces to tabs). Signed-off-by: Philo Lu <lulie@linux.alibaba.com> Link: https://lore.kernel.org/r/20240911033719.91468-6-lulie@linux.alibaba.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-09-11selftests/bpf: Add test for __nullable suffix in tp_btfPhilo Lu1-0/+24
Add a tracepoint with __nullable suffix in bpf_testmod, and add cases for it: $ ./test_progs -t "tp_btf_nullable" #406/1 tp_btf_nullable/handle_tp_btf_nullable_bare1:OK #406/2 tp_btf_nullable/handle_tp_btf_nullable_bare2:OK #406 tp_btf_nullable:OK Summary: 1/2 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Philo Lu <lulie@linux.alibaba.com> Link: https://lore.kernel.org/r/20240911033719.91468-3-lulie@linux.alibaba.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-09-10bpf: Fix error message on kfunc arg type mismatchMaxim Mikityanskiy1-0/+7
When "arg#%d expected pointer to ctx, but got %s" error is printed, both template parts actually point to the type of the argument, therefore, it will also say "but got PTR", regardless of what was the actual register type. Fix the message to print the register type in the second part of the template, change the existing test to adapt to the new format, and add a new test to test the case when arg is a pointer to context, but reg is a scalar. Fixes: 00b85860feb8 ("bpf: Rewrite kfunc argument handling") Signed-off-by: Maxim Mikityanskiy <maxim@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/bpf/20240909133909.1315460-1-maxim@isovalent.com