kernel/linux.git/tools/lib/bpf, branch v6.1.168

bpftool: Fix truncated netlink dumps

2026-03-04T12:20:06+00:00

[ Upstream commit 3b39d73cc3379360a33eb583b17f21fe55e1288e ] Netlink requires that the recv buffer used during dumps is at least min(PAGE_SIZE, 8k) (see the man page). Otherwise the messages will get truncated. Make sure bpftool follows this requirement, avoid missing information on systems with large pages. Acked-by: Quentin Monnet Fixes: 7084566a236f ("tools/bpftool: Remove libbpf_internal.h usage in bpftool") Signed-off-by: Jakub Kicinski Link: https://lore.kernel.org/r/20260217194150.734701-1-kuba@kernel.org Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

libbpf: Fix OOB read in btf_dump_get_bitfield_value

2026-03-04T12:19:26+00:00

[ Upstream commit 5714ca8cba5ed736f3733663c446cbee63a10a64 ] When dumping bitfield data, btf_dump_get_bitfield_value() reads data based on the underlying type's size (t->size). However, it does not verify that the provided data buffer (data_sz) is large enough to contain these bytes. If btf_dump__dump_type_data() is called with a buffer smaller than the type's size, this leads to an out-of-bounds read. This was confirmed by AddressSanitizer in the linked issue. Fix this by ensuring we do not read past the provided data_sz limit. Fixes: a1d3cc3c5eca ("libbpf: Avoid use of __int128 in typed dump display") Reported-by: Harrison Green Suggested-by: Alan Maguire Signed-off-by: Varun R Mallya Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20260106233527.163487-1-varunrmallya@gmail.com Closes: https://github.com/libbpf/libbpf/issues/928 Signed-off-by: Sasha Levin

libbpf: Fix powerpc's stack register definition in bpf_tracing.h

2025-12-06T21:12:12+00:00

[ Upstream commit 7221b9caf84b3294688228a19273d74ea19a2ee4 ] retsnoop's build on powerpc (ppc64le) architecture ([0]) failed due to wrong definition of PT_REGS_SP() macro. Looking at powerpc's implementation of stack unwinding in perf_callchain_user_64() clearly shows that stack pointer register is gpr[1]. Fix libbpf's definition of __PT_SP_REG for powerpc to fix all this. [0] https://kojipkgs.fedoraproject.org/work/tasks/1544/137921544/build.log Fixes: 138d6153a139 ("samples/bpf: Enable powerpc support") Signed-off-by: Andrii Nakryiko Reviewed-by: Naveen N Rao (AMD) Link: https://lore.kernel.org/r/20251020203643.989467-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

libbpf: Fix reuse of DEVMAP

2025-10-15T09:56:26+00:00

[ Upstream commit 6c6b4146deb12d20f42490d5013f2043df942161 ] Previously, re-using pinned DEVMAP maps would always fail, because get_map_info on a DEVMAP always returns flags with BPF_F_RDONLY_PROG set, but BPF_F_RDONLY_PROG being set on a map during creation is invalid. Thus, ignore the BPF_F_RDONLY_PROG flag in the flags returned from get_map_info when checking for compatibility with an existing DEVMAP. The same problem is handled in a third-party ebpf library: - https://github.com/cilium/ebpf/issues/925 - https://github.com/cilium/ebpf/pull/930 Fixes: 0cdbb4b09a06 ("devmap: Allow map lookups from eBPF") Signed-off-by: Yureka Lilian Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20250814180113.1245565-3-yuka@yuka.dev Signed-off-by: Sasha Levin

libbpf: Fix null pointer dereference in btf_dump__free on allocation failure

2025-07-06T08:58:00+00:00

[ Upstream commit aa485e8789d56a4573f7c8d000a182b749eaa64d ] When btf_dump__new() fails to allocate memory for the internal hashmap (btf_dump->type_names), it returns an error code. However, the cleanup function btf_dump__free() does not check if btf_dump->type_names is NULL before attempting to free it. This leads to a null pointer dereference when btf_dump__free() is called on a btf_dump object. Fixes: 351131b51c7a ("libbpf: add btf_dump API for BTF-to-C conversion") Signed-off-by: Yuan Chen Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20250618011933.11423-1-chenyuan_fl@163.com Signed-off-by: Sasha Levin

libbpf: Add identical pointer detection to btf_dedup_is_equiv()

2025-06-27T10:07:34+00:00

[ Upstream commit 8e64c387c942229c551d0f23de4d9993d3a2acb6 ] Recently as a side-effect of commit ac053946f5c4 ("compiler.h: introduce TYPEOF_UNQUAL() macro") issues were observed in deduplication between modules and kernel BTF such that a large number of kernel types were not deduplicated so were found in module BTF (task_struct, bpf_prog etc). The root cause appeared to be a failure to dedup struct types, specifically those with members that were pointers with __percpu annotations. The issue in dedup is at the point that we are deduplicating structures, we have not yet deduplicated reference types like pointers. If multiple copies of a pointer point at the same (deduplicated) integer as in this case, we do not see them as identical. Special handling already exists to deal with structures and arrays, so add pointer handling here too. Reported-by: Alexei Starovoitov Signed-off-by: Alan Maguire Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20250429161042.2069678-1-alan.maguire@oracle.com Signed-off-by: Sasha Levin

libbpf: Use proper errno value in nlattr

2025-06-27T10:07:11+00:00

[ Upstream commit fd5fd538a1f4b34cee6823ba0ddda2f7a55aca96 ] Return value of the validate_nla() function can be propagated all the way up to users of libbpf API. In case of error this libbpf version of validate_nla returns -1 which will be seen as -EPERM from user's point of view. Instead, return a more reasonable -EINVAL. Fixes: bbf48c18ee0c ("libbpf: add error reporting in XDP") Suggested-by: Andrii Nakryiko Signed-off-by: Anton Protopopov Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20250510182011.2246631-1-a.s.protopopov@gmail.com Signed-off-by: Sasha Levin

bpf: Fix uninitialized values in BPF_{CORE,PROBE}_READ

2025-06-27T10:07:10+00:00

[ Upstream commit 41d4ce6df3f4945341ec509a840cc002a413b6cc ] With the latest LLVM bpf selftests build will fail with the following error message: progs/profiler.inc.h:710:31: error: default initialization of an object of type 'typeof ((parent_task)->real_cred->uid.val)' (aka 'const unsigned int') leaves the object uninitialized and is incompatible with C++ [-Werror,-Wdefault-const-init-unsafe] 710 | proc_exec_data->parent_uid = BPF_CORE_READ(parent_task, real_cred, uid.val); | ^ tools/testing/selftests/bpf/tools/include/bpf/bpf_core_read.h:520:35: note: expanded from macro 'BPF_CORE_READ' 520 | ___type((src), a, ##__VA_ARGS__) __r; \ | ^ This happens because BPF_CORE_READ (and other macro) declare the variable __r using the ___type macro which can inherit const modifier from intermediate types. Fix this by using __typeof_unqual__, when supported. (And when it is not supported, the problem shouldn't appear, as older compilers haven't complained.) Fixes: 792001f4f7aa ("libbpf: Add user-space variants of BPF_CORE_READ() family of macros") Fixes: a4b09a9ef945 ("libbpf: Add non-CO-RE variants of BPF_CORE_READ() macro family") Signed-off-by: Anton Protopopov Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20250502193031.3522715-1-a.s.protopopov@gmail.com Signed-off-by: Sasha Levin

libbpf: Use proper errno value in linker

2025-06-27T10:07:10+00:00

[ Upstream commit 358b1c0f56ebb6996fcec7dcdcf6bae5dcbc8b6c ] Return values of the linker_append_sec_data() and the linker_append_elf_relos() functions are propagated all the way up to users of libbpf API. In some error cases these functions return -1 which will be seen as -EPERM from user's point of view. Instead, return a more reasonable -EINVAL. Fixes: faf6ed321cf6 ("libbpf: Add BPF static linker APIs") Signed-off-by: Anton Protopopov Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20250430120820.2262053-1-a.s.protopopov@gmail.com Signed-off-by: Sasha Levin

libbpf: Fix buffer overflow in bpf_object__init_prog

2025-06-27T10:07:09+00:00

[ Upstream commit ee684de5c1b0ac01821320826baec7da93f3615b ] As shown in [1], it is possible to corrupt a BPF ELF file such that arbitrary BPF instructions are loaded by libbpf. This can be done by setting a symbol (BPF program) section offset to a large (unsigned) number such that

overflows and points before the section data in the memory. Consider the situation below where: - prog_start = sec_start + symbol_offset <-- size_t overflow here - prog_end = prog_start + prog_size prog_start sec_start prog_end sec_end | | | | v v v v .....................|################################|............ The report in [1] also provides a corrupted BPF ELF which can be used as a reproducer: $ readelf -S crash Section Headers: [Nr] Name Type Address Offset Size EntSize Flags Link Info Align ... [ 2] uretprobe.mu[...] PROGBITS 0000000000000000 00000040 0000000000000068 0000000000000000 AX 0 0 8 $ readelf -s crash Symbol table '.symtab' contains 8 entries: Num: Value Size Type Bind Vis Ndx Name ... 6: ffffffffffffffb8 104 FUNC GLOBAL DEFAULT 2 handle_tp Here, the handle_tp prog has section offset ffffffffffffffb8, i.e. will point before the actual memory where section 2 is allocated. This is also reported by AddressSanitizer: ================================================================= ==1232==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x7c7302fe0000 at pc 0x7fc3046e4b77 bp 0x7ffe64677cd0 sp 0x7ffe64677490 READ of size 104 at 0x7c7302fe0000 thread T0 #0 0x7fc3046e4b76 in memcpy (/lib64/libasan.so.8+0xe4b76) #1 0x00000040df3e in bpf_object__init_prog /src/libbpf/src/libbpf.c:856 #2 0x00000040df3e in bpf_object__add_programs /src/libbpf/src/libbpf.c:928 #3 0x00000040df3e in bpf_object__elf_collect /src/libbpf/src/libbpf.c:3930 #4 0x00000040df3e in bpf_object_open /src/libbpf/src/libbpf.c:8067 #5 0x00000040f176 in bpf_object__open_file /src/libbpf/src/libbpf.c:8090 #6 0x000000400c16 in main /poc/poc.c:8 #7 0x7fc3043d25b4 in __libc_start_call_main (/lib64/libc.so.6+0x35b4) #8 0x7fc3043d2667 in __libc_start_main@@GLIBC_2.34 (/lib64/libc.so.6+0x3667) #9 0x000000400b34 in _start (/poc/poc+0x400b34) 0x7c7302fe0000 is located 64 bytes before 104-byte region [0x7c7302fe0040,0x7c7302fe00a8) allocated by thread T0 here: #0 0x7fc3046e716b in malloc (/lib64/libasan.so.8+0xe716b) #1 0x7fc3045ee600 in __libelf_set_rawdata_wrlock (/lib64/libelf.so.1+0xb600) #2 0x7fc3045ef018 in __elf_getdata_rdlock (/lib64/libelf.so.1+0xc018) #3 0x00000040642f in elf_sec_data /src/libbpf/src/libbpf.c:3740 The problem here is that currently, libbpf only checks that the program end is within the section bounds. There used to be a check `while (sec_off < sec_sz)` in bpf_object__add_programs, however, it was removed by commit 6245947c1b3c ("libbpf: Allow gaps in BPF program sections to support overriden weak functions"). Add a check for detecting the overflow of `sec_off + prog_sz` to bpf_object__init_prog to fix this issue. [1] https://github.com/lmarch2/poc/blob/main/libbpf/libbpf.md Fixes: 6245947c1b3c ("libbpf: Allow gaps in BPF program sections to support overriden weak functions") Reported-by: lmarch2 <2524158037@qq.com> Signed-off-by: Viktor Malik Signed-off-by: Andrii Nakryiko Reviewed-by: Shung-Hsi Yu Link: https://github.com/lmarch2/poc/blob/main/libbpf/libbpf.md Link: https://lore.kernel.org/bpf/20250415155014.397603-1-vmalik@redhat.com Signed-off-by: Sasha Levin