kernel/linux.git/net/bpf, branch v5.10.258

bpf: reject short IPv4/IPv6 inputs in bpf_prog_test_run_skb

2026-06-01T15:29:31+00:00

[ Upstream commit 12bec2bd4b76d81c5d3996bd14ec1b7f4d983747 ] bpf_prog_test_run_skb() calls eth_type_trans() first and then uses skb->protocol to initialize sk family and address fields for the test run. For IPv4 and IPv6 packets, it may access ip_hdr(skb) or ipv6_hdr(skb) even when the provided test input only contains an Ethernet header. Reject the input earlier if the Ethernet frame carries IPv4/IPv6 EtherType but the L3 header is too short. Fold the IPv4/IPv6 header length checks into the existing protocol switch and return -EINVAL before accessing the network headers. Fixes: fa5cb548ced6 ("bpf: Setup socket family and addresses in bpf_prog_test_run_skb") Reported-by: syzbot+619b9ef527f510a57cfc@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=619b9ef527f510a57cfc Signed-off-by: Sun Jian Link: https://lore.kernel.org/r/20260408034623.180320-2-sun.jian.kdev@gmail.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

bpf: Do not let BPF test infra emit invalid GSO types to stack

2026-02-06T15:40:09+00:00

commit 04a899573fb87273a656f178b5f920c505f68875 upstream. Yinhao et al. reported that their fuzzer tool was able to trigger a skb_warn_bad_offload() from netif_skb_features() -> gso_features_check(). When a BPF program - triggered via BPF test infra - pushes the packet to the loopback device via bpf_clone_redirect() then mentioned offload warning can be seen. GSO-related features are then rightfully disabled. We get into this situation due to convert___skb_to_skb() setting gso_segs and gso_size but not gso_type. Technically, it makes sense that this warning triggers since the GSO properties are malformed due to the gso_type. Potentially, the gso_type could be marked non-trustworthy through setting it at least to SKB_GSO_DODGY without any other specific assumptions, but that also feels wrong given we should not go further into the GSO engine in the first place. The checks were added in 121d57af308d ("gso: validate gso_type in GSO handlers") because there were malicious (syzbot) senders that combine a protocol with a non-matching gso_type. If we would want to drop such packets, gso_features_check() currently only returns feature flags via netif_skb_features(), so one location for potentially dropping such skbs could be validate_xmit_unreadable_skb(), but then otoh it would be an additional check in the fast-path for a very corner case. Given bpf_clone_redirect() is the only place where BPF test infra could emit such packets, lets reject them right there. Fixes: 850a88cc4096 ("bpf: Expose __sk_buff wire_len/gso_segs to BPF_PROG_TEST_RUN") Fixes: cf62089b0edd ("bpf: Add gso_size to __sk_buff") Reported-by: Yinhao Hu Reported-by: Kaiyan Mei Reported-by: Dongliang Mu Signed-off-by: Daniel Borkmann Signed-off-by: Martin KaFai Lau Link: https://patch.msgid.link/20251020075441.127980-1-daniel@iogearbox.net Signed-off-by: Shung-Hsi Yu Signed-off-by: Greg Kroah-Hartman

bpf: Move skb->len == 0 checks into __bpf_redirect

2023-01-14T09:15:31+00:00

[ Upstream commit 114039b342014680911c35bd6b72624180fd669a ] To avoid potentially breaking existing users. Both mac/no-mac cases have to be amended; mac_header >= network_header is not enough (verified with a new test, see next patch). Fixes: fd1894224407 ("bpf: Don't redirect packets with invalid pkt_len") Signed-off-by: Stanislav Fomichev Link: https://lore.kernel.org/r/20221121180340.1983627-1-sdf@google.com Signed-off-by: Martin KaFai Lau Signed-off-by: Sasha Levin

bpf, test_run: Fix alignment problem in bpf_prog_test_run_skb()

2022-11-25T16:45:43+00:00

[ Upstream commit d3fd203f36d46aa29600a72d57a1b61af80e4a25 ] We got a syzkaller problem because of aarch64 alignment fault if KFENCE enabled. When the size from user bpf program is an odd number, like 399, 407, etc, it will cause the struct skb_shared_info's unaligned access. As seen below: BUG: KFENCE: use-after-free read in __skb_clone+0x23c/0x2a0 net/core/skbuff.c:1032 Use-after-free read at 0xffff6254fffac077 (in kfence-#213): __lse_atomic_add arch/arm64/include/asm/atomic_lse.h:26 [inline] arch_atomic_add arch/arm64/include/asm/atomic.h:28 [inline] arch_atomic_inc include/linux/atomic-arch-fallback.h:270 [inline] atomic_inc include/asm-generic/atomic-instrumented.h:241 [inline] __skb_clone+0x23c/0x2a0 net/core/skbuff.c:1032 skb_clone+0xf4/0x214 net/core/skbuff.c:1481 ____bpf_clone_redirect net/core/filter.c:2433 [inline] bpf_clone_redirect+0x78/0x1c0 net/core/filter.c:2420 bpf_prog_d3839dd9068ceb51+0x80/0x330 bpf_dispatcher_nop_func include/linux/bpf.h:728 [inline] bpf_test_run+0x3c0/0x6c0 net/bpf/test_run.c:53 bpf_prog_test_run_skb+0x638/0xa7c net/bpf/test_run.c:594 bpf_prog_test_run kernel/bpf/syscall.c:3148 [inline] __do_sys_bpf kernel/bpf/syscall.c:4441 [inline] __se_sys_bpf+0xad0/0x1634 kernel/bpf/syscall.c:4381 kfence-#213: 0xffff6254fffac000-0xffff6254fffac196, size=407, cache=kmalloc-512 allocated by task 15074 on cpu 0 at 1342.585390s: kmalloc include/linux/slab.h:568 [inline] kzalloc include/linux/slab.h:675 [inline] bpf_test_init.isra.0+0xac/0x290 net/bpf/test_run.c:191 bpf_prog_test_run_skb+0x11c/0xa7c net/bpf/test_run.c:512 bpf_prog_test_run kernel/bpf/syscall.c:3148 [inline] __do_sys_bpf kernel/bpf/syscall.c:4441 [inline] __se_sys_bpf+0xad0/0x1634 kernel/bpf/syscall.c:4381 __arm64_sys_bpf+0x50/0x60 kernel/bpf/syscall.c:4381 To fix the problem, we adjust @size so that (@size + @hearoom) is a multiple of SMP_CACHE_BYTES. So we make sure the struct skb_shared_info is aligned to a cache line. Fixes: 1cf1cae963c2 ("bpf: introduce BPF_PROG_TEST_RUN command") Signed-off-by: Baisong Zhong Signed-off-by: Daniel Borkmann Cc: Eric Dumazet Link: https://lore.kernel.org/bpf/20221102081620.1465154-1-zhongbaisong@huawei.com Signed-off-by: Sasha Levin

bpf: Don't redirect packets with invalid pkt_len

2022-09-05T08:28:56+00:00

commit fd1894224407c484f652ad456e1ce423e89bb3eb upstream. Syzbot found an issue [1]: fq_codel_drop() try to drop a flow whitout any skbs, that is, the flow->head is null. The root cause, as the [2] says, is because that bpf_prog_test_run_skb() run a bpf prog which redirects empty skbs. So we should determine whether the length of the packet modified by bpf prog or others like bpf_prog_test is valid before forwarding it directly. LINK: [1] https://syzkaller.appspot.com/bug?id=0b84da80c2917757915afa89f7738a9d16ec96c5 LINK: [2] https://www.spinics.net/lists/netdev/msg777503.html Reported-by: syzbot+7a12909485b94426aceb@syzkaller.appspotmail.com Signed-off-by: Zhengchao Shao Reviewed-by: Stanislav Fomichev Link: https://lore.kernel.org/r/20220715115559.139691-1-shaozhengchao@huawei.com Signed-off-by: Alexei Starovoitov Signed-off-by: Greg Kroah-Hartman

bpf: Add PROG_TEST_RUN support for sk_lookup programs

2022-08-03T10:00:52+00:00

commit 7c32e8f8bc33a5f4b113a630857e46634e3e143b upstream. Allow to pass sk_lookup programs to PROG_TEST_RUN. User space provides the full bpf_sk_lookup struct as context. Since the context includes a socket pointer that can't be exposed to user space we define that PROG_TEST_RUN returns the cookie of the selected socket or zero in place of the socket pointer. We don't support testing programs that select a reuseport socket, since this would mean running another (unrelated) BPF program from the sk_lookup test handler. Signed-off-by: Lorenz Bauer Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20210303101816.36774-3-lmb@cloudflare.com Signed-off-by: Tianchen Ding Signed-off-by: Greg Kroah-Hartman

bpf: Consolidate shared test timing code

2022-08-03T10:00:52+00:00

commit 607b9cc92bd7208338d714a22b8082fe83bcb177 upstream. Share the timing / signal interruption logic between different implementations of PROG_TEST_RUN. There is a change in behaviour as well. We check the loop exit condition before checking for pending signals. This resolves an edge case where a signal arrives during the last iteration. Instead of aborting with EINTR we return the successful result to user space. Signed-off-by: Lorenz Bauer Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20210303101816.36774-2-lmb@cloudflare.com [dtcccc: fix conflicts in bpf_test_run()] Signed-off-by: Tianchen Ding Signed-off-by: Greg Kroah-Hartman

bpf, test, cgroup: Use sk_{alloc,free} for test cases

2021-10-27T07:56:56+00:00

commit 435b08ec0094ac1e128afe6cfd0d9311a8c617a7 upstream. BPF test infra has some hacks in place which kzalloc() a socket and perform minimum init via sock_net_set() and sock_init_data(). As a result, the sk's skcd->cgroup is NULL since it didn't go through proper initialization as it would have been the case from sk_alloc(). Rather than re-adding a NULL test in sock_cgroup_ptr() just for this, use sk_{alloc,free}() pair for the test socket. The latter also allows to get rid of the bpf_sk_storage_free() special case. Fixes: 8520e224f547 ("bpf, cgroups: Fix cgroup v2 fallback on v1/v2 mixed mode") Fixes: b7a1848e8398 ("bpf: add BPF_PROG_TEST_RUN support for flow dissector") Fixes: 2cb494a36c98 ("bpf: add tests for direct packet access from CGROUP_SKB") Reported-by: syzbot+664b58e9a40fbb2cec71@syzkaller.appspotmail.com Reported-by: syzbot+33f36d0754d4c5c0e102@syzkaller.appspotmail.com Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov Tested-by: syzbot+664b58e9a40fbb2cec71@syzkaller.appspotmail.com Tested-by: syzbot+33f36d0754d4c5c0e102@syzkaller.appspotmail.com Link: https://lore.kernel.org/bpf/20210927123921.21535-2-daniel@iogearbox.net Signed-off-by: Greg Kroah-Hartman

bpf: Fix NULL pointer dereference in bpf_get_local_storage() helper

2021-09-03T08:09:21+00:00

commit b910eaaaa4b89976ef02e5d6448f3f73dc671d91 upstream. Jiri Olsa reported a bug ([1]) in kernel where cgroup local storage pointer may be NULL in bpf_get_local_storage() helper. There are two issues uncovered by this bug: (1). kprobe or tracepoint prog incorrectly sets cgroup local storage before prog run, (2). due to change from preempt_disable to migrate_disable, preemption is possible and percpu storage might be overwritten by other tasks. This issue (1) is fixed in [2]. This patch tried to address issue (2). The following shows how things can go wrong: task 1: bpf_cgroup_storage_set() for percpu local storage preemption happens task 2: bpf_cgroup_storage_set() for percpu local storage preemption happens task 1: run bpf program task 1 will effectively use the percpu local storage setting by task 2 which will be either NULL or incorrect ones. Instead of just one common local storage per cpu, this patch fixed the issue by permitting 8 local storages per cpu and each local storage is identified by a task_struct pointer. This way, we allow at most 8 nested preemption between bpf_cgroup_storage_set() and bpf_cgroup_storage_unset(). The percpu local storage slot is released (calling bpf_cgroup_storage_unset()) by the same task after bpf program finished running. bpf_test_run() is also fixed to use the new bpf_cgroup_storage_set() interface. The patch is tested on top of [2] with reproducer in [1]. Without this patch, kernel will emit error in 2-3 minutes. With this patch, after one hour, still no error. [1] https://lore.kernel.org/bpf/CAKH8qBuXCfUz=w8L+Fj74OaUpbosO29niYwTki7e3Ag044_aww@mail.gmail.com/T [2] https://lore.kernel.org/bpf/20210309185028.3763817-1-yhs@fb.com Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Acked-by: Roman Gushchin Link: https://lore.kernel.org/bpf/20210323055146.3334476-1-yhs@fb.com Cc: # 5.10.x Signed-off-by: Stanislav Fomichev Signed-off-by: Sasha Levin

bpf, test: fix NULL pointer dereference on invalid expected_attach_type

2021-07-28T12:35:37+00:00

[ Upstream commit 5e21bb4e812566aef86fbb77c96a4ec0782286e4 ] These two types of XDP progs (BPF_XDP_DEVMAP, BPF_XDP_CPUMAP) will not be executed directly in the driver, therefore we should also not directly run them from here. To run in these two situations, there must be further preparations done, otherwise these may cause a kernel panic. For more details, see also dev_xdp_attach(). [ 46.982479] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 46.984295] #PF: supervisor read access in kernel mode [ 46.985777] #PF: error_code(0x0000) - not-present page [ 46.987227] PGD 800000010dca4067 P4D 800000010dca4067 PUD 10dca6067 PMD 0 [ 46.989201] Oops: 0000 [#1] SMP PTI [ 46.990304] CPU: 7 PID: 562 Comm: a.out Not tainted 5.13.0+ #44 [ 46.992001] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/24 [ 46.995113] RIP: 0010:___bpf_prog_run+0x17b/0x1710 [ 46.996586] Code: 49 03 14 cc e8 76 f6 fe ff e9 ad fe ff ff 0f b6 43 01 48 0f bf 4b 02 48 83 c3 08 89 c2 83 e0 0f c0 ea 04 02 [ 47.001562] RSP: 0018:ffffc900005afc58 EFLAGS: 00010246 [ 47.003115] RAX: 0000000000000000 RBX: ffffc9000023f068 RCX: 0000000000000000 [ 47.005163] RDX: 0000000000000000 RSI: 0000000000000079 RDI: ffffc900005afc98 [ 47.007135] RBP: 0000000000000000 R08: ffffc9000023f048 R09: c0000000ffffdfff [ 47.009171] R10: 0000000000000001 R11: ffffc900005afb40 R12: ffffc900005afc98 [ 47.011172] R13: 0000000000000001 R14: 0000000000000001 R15: ffffffff825258a8 [ 47.013244] FS: 00007f04a5207580(0000) GS:ffff88842fdc0000(0000) knlGS:0000000000000000 [ 47.015705] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 47.017475] CR2: 0000000000000000 CR3: 0000000100182005 CR4: 0000000000770ee0 [ 47.019558] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 47.021595] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 47.023574] PKRU: 55555554 [ 47.024571] Call Trace: [ 47.025424] __bpf_prog_run32+0x32/0x50 [ 47.026296] ? printk+0x53/0x6a [ 47.027066] ? ktime_get+0x39/0x90 [ 47.027895] bpf_test_run.cold.28+0x23/0x123 [ 47.028866] ? printk+0x53/0x6a [ 47.029630] bpf_prog_test_run_xdp+0x149/0x1d0 [ 47.030649] __sys_bpf+0x1305/0x23d0 [ 47.031482] __x64_sys_bpf+0x17/0x20 [ 47.032316] do_syscall_64+0x3a/0x80 [ 47.033165] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 47.034254] RIP: 0033:0x7f04a51364dd [ 47.035133] Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 48 [ 47.038768] RSP: 002b:00007fff8f9fc518 EFLAGS: 00000213 ORIG_RAX: 0000000000000141 [ 47.040344] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f04a51364dd [ 47.041749] RDX: 0000000000000048 RSI: 0000000020002a80 RDI: 000000000000000a [ 47.043171] RBP: 00007fff8f9fc530 R08: 0000000002049300 R09: 0000000020000100 [ 47.044626] R10: 0000000000000004 R11: 0000000000000213 R12: 0000000000401070 [ 47.046088] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 47.047579] Modules linked in: [ 47.048318] CR2: 0000000000000000 [ 47.049120] ---[ end trace 7ad34443d5be719a ]--- [ 47.050273] RIP: 0010:___bpf_prog_run+0x17b/0x1710 [ 47.051343] Code: 49 03 14 cc e8 76 f6 fe ff e9 ad fe ff ff 0f b6 43 01 48 0f bf 4b 02 48 83 c3 08 89 c2 83 e0 0f c0 ea 04 02 [ 47.054943] RSP: 0018:ffffc900005afc58 EFLAGS: 00010246 [ 47.056068] RAX: 0000000000000000 RBX: ffffc9000023f068 RCX: 0000000000000000 [ 47.057522] RDX: 0000000000000000 RSI: 0000000000000079 RDI: ffffc900005afc98 [ 47.058961] RBP: 0000000000000000 R08: ffffc9000023f048 R09: c0000000ffffdfff [ 47.060390] R10: 0000000000000001 R11: ffffc900005afb40 R12: ffffc900005afc98 [ 47.061803] R13: 0000000000000001 R14: 0000000000000001 R15: ffffffff825258a8 [ 47.063249] FS: 00007f04a5207580(0000) GS:ffff88842fdc0000(0000) knlGS:0000000000000000 [ 47.065070] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 47.066307] CR2: 0000000000000000 CR3: 0000000100182005 CR4: 0000000000770ee0 [ 47.067747] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 47.069217] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 47.070652] PKRU: 55555554 [ 47.071318] Kernel panic - not syncing: Fatal exception [ 47.072854] Kernel Offset: disabled [ 47.073683] ---[ end Kernel panic - not syncing: Fatal exception ]--- Fixes: 9216477449f3 ("bpf: cpumap: Add the possibility to attach an eBPF program to cpumap") Fixes: fbee97feed9b ("bpf: Add support to attach bpf program to a devmap entry") Reported-by: Abaci Signed-off-by: Xuan Zhuo Signed-off-by: Daniel Borkmann Reviewed-by: Dust Li Acked-by: Jesper Dangaard Brouer Acked-by: David Ahern Acked-by: Song Liu Link: https://lore.kernel.org/bpf/20210708080409.73525-1-xuanzhuo@linux.alibaba.com Signed-off-by: Sasha Levin