kernel/linux.git/include/linux/filter.h, branch v6.6.132

bpf: Fix invalid prog->stats access when update_effective_progs fails

2026-01-11T14:21:25+00:00

[ Upstream commit 7dc211c1159d991db609bdf4b0fb9033c04adcbc ] Syzkaller triggers an invalid memory access issue following fault injection in update_effective_progs. The issue can be described as follows: __cgroup_bpf_detach update_effective_progs compute_effective_progs bpf_prog_array_alloc <-- fault inject purge_effective_progs /* change to dummy_bpf_prog */ array->items[index] = &dummy_bpf_prog.prog ---softirq start--- __do_softirq ... __cgroup_bpf_run_filter_skb __bpf_prog_run_save_cb bpf_prog_run stats = this_cpu_ptr(prog->stats) /* invalid memory access */ flags = u64_stats_update_begin_irqsave(&stats->syncp) ---softirq end--- static_branch_dec(&cgroup_bpf_enabled_key[atype]) The reason is that fault injection caused update_effective_progs to fail and then changed the original prog into dummy_bpf_prog.prog in purge_effective_progs. Then a softirq came, and accessing the members of dummy_bpf_prog.prog in the softirq triggers invalid mem access. To fix it, skip updating stats when stats is NULL. Fixes: 492ecee892c2 ("bpf: enable program stats") Signed-off-by: Pu Lehui Link: https://lore.kernel.org/r/20251115102343.2200727-1-pulehui@huaweicloud.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

bpf: Improve program stats run-time calculation

2026-01-11T14:21:25+00:00

[ Upstream commit ce09cbdd988887662546a1175bcfdfc6c8fdd150 ] This patch improves the run-time calculation for program stats by capturing the duration as soon as possible after the program returns. Previously, the duration included u64_stats_t operations. While the instrumentation overhead is part of the total time spent when stats are enabled, distinguishing between the program's native execution time and the time spent due to instrumentation is crucial for accurate performance analysis. By making this change, the patch facilitates more precise optimization of BPF programs, enabling users to understand their performance in environments without stats enabled. I used a virtualized environment to measure the run-time over one minute for a basic raw_tracepoint/sys_enter program, which just increments a local counter. Although the virtualization introduced some performance degradation that could affect the results, I observed approximately a 16% decrease in average run-time reported by stats with this change (310 -> 260 nsec). Signed-off-by: Jose Fernandez Signed-off-by: Daniel Borkmann Acked-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20240402034010.25060-1-josef@netflix.com Stable-dep-of: 7dc211c1159d ("bpf: Fix invalid prog->stats access when update_effective_progs fails") Signed-off-by: Sasha Levin

bpf: Add bpf_prog_run_data_pointers()

2025-11-24T09:30:04+00:00

[ Upstream commit 4ef92743625818932b9c320152b58274c05e5053 ] syzbot found that cls_bpf_classify() is able to change tc_skb_cb(skb)->drop_reason triggering a warning in sk_skb_reason_drop(). WARNING: CPU: 0 PID: 5965 at net/core/skbuff.c:1192 __sk_skb_reason_drop net/core/skbuff.c:1189 [inline] WARNING: CPU: 0 PID: 5965 at net/core/skbuff.c:1192 sk_skb_reason_drop+0x76/0x170 net/core/skbuff.c:1214 struct tc_skb_cb has been added in commit ec624fe740b4 ("net/sched: Extend qdisc control block with tc control block"), which added a wrong interaction with db58ba459202 ("bpf: wire in data and data_end for cls_act_bpf"). drop_reason was added later. Add bpf_prog_run_data_pointers() helper to save/restore the net_sched storage colliding with BPF data_meta/data_end. Fixes: ec624fe740b4 ("net/sched: Extend qdisc control block with tc control block") Reported-by: syzbot Closes: https://lore.kernel.org/netdev/6913437c.a70a0220.22f260.013b.GAE@google.com/ Signed-off-by: Eric Dumazet Signed-off-by: Martin KaFai Lau Reviewed-by: Victor Nogueira Acked-by: Jamal Hadi Salim Link: https://patch.msgid.link/20251112125516.1563021-1-edumazet@google.com Signed-off-by: Sasha Levin

bpf: Don't use %pK through printk

2025-11-24T09:29:17+00:00

[ Upstream commit 2caa6b88e0ba0231fb4ff0ba8e73cedd5fb81fc8 ] In the past %pK was preferable to %p as it would not leak raw pointer values into the kernel log. Since commit ad67b74d2469 ("printk: hash addresses printed with %p") the regular %p has been improved to avoid this issue. Furthermore, restricted pointers ("%pK") were never meant to be used through printk(). They can still unintentionally leak raw pointers or acquire sleeping locks in atomic contexts. Switch to the regular pointer formatting which is safer and easier to reason about. Signed-off-by: Thomas Weißschuh Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20250811-restricted-pointers-bpf-v1-1-a1d7cc3cb9e7@linutronix.de Signed-off-by: Sasha Levin

bpf: refactor bpf_helper_changes_pkt_data to use helper number

2025-05-09T07:43:54+00:00

commit b238e187b4a2d3b54d80aec05a9cab6466b79dde upstream. Use BPF helper number instead of function pointer in bpf_helper_changes_pkt_data(). This would simplify usage of this function in verifier.c:check_cfg() (in a follow-up patch), where only helper number is easily available and there is no real need to lookup helper proto. Signed-off-by: Eduard Zingerman Link: https://lore.kernel.org/r/20241210041100.1898468-3-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov Signed-off-by: Shung-Hsi Yu Signed-off-by: Greg Kroah-Hartman

Revert "bpf: Take return from set_memory_ro() into account with bpf_prog_lock_ro()"

2024-07-09T09:44:29+00:00

This reverts commit fdd411af8178edc6b7bf260f8fa4fba1bedd0a6d which is commit 7d2cc63eca0c993c99d18893214abf8f85d566d8 upstream. It is part of a series that is reported to both break the arm64 builds and instantly crashes the powerpc systems at the first load of a bpf program. So revert it for now until it can come back in a safe way. Reported-by: matoro Reported-by: Vitaly Chikunov Reported-by: WangYuli Link: https://lore.kernel.org/r/5A29E00D83AB84E3+20240706031101.637601-1-wangyuli@uniontech.com Link: https://lore.kernel.org/r/cf736c5e37489e7dc7ffd67b9de2ab47@matoro.tk Cc: Hari Bathini Cc: Song Liu Cc: Michael Ellerman Cc: Christophe Leroy Cc: Kees Cook Cc: Puranjay Mohan Cc: Ilya Leoshkevich # s390x Cc: Tiezhu Yang # LoongArch Cc: Johan Almbladh # MIPS Part Cc: Alexei Starovoitov Cc: Sasha Levin Signed-off-by: Greg Kroah-Hartman

Revert "bpf: Take return from set_memory_rox() into account with bpf_jit_binary_lock_ro()"

2024-07-09T09:44:29+00:00

This reverts commit 08f6c05feb1db21653e98ca84ea04ca032d014c7 which is commit e60adf513275c3a38e5cb67f7fd12387e43a3ff5 upstream. It is part of a series that is reported to both break the arm64 builds and instantly crashes the powerpc systems at the first load of a bpf program. So revert it for now until it can come back in a safe way. Reported-by: matoro Reported-by: Vitaly Chikunov Reported-by: WangYuli Link: https://lore.kernel.org/r/5A29E00D83AB84E3+20240706031101.637601-1-wangyuli@uniontech.com Link: https://lore.kernel.org/r/cf736c5e37489e7dc7ffd67b9de2ab47@matoro.tk Cc: Hari Bathini Cc: Song Liu Cc: Michael Ellerman Cc: Christophe Leroy Cc: Kees Cook Cc: Puranjay Mohan Cc: Ilya Leoshkevich # s390x Cc: Tiezhu Yang # LoongArch Cc: Johan Almbladh # MIPS Part Cc: Alexei Starovoitov Cc: Sasha Levin Signed-off-by: Greg Kroah-Hartman

bpf: Take return from set_memory_rox() into account with bpf_jit_binary_lock_ro()

2024-07-05T07:33:50+00:00

[ Upstream commit e60adf513275c3a38e5cb67f7fd12387e43a3ff5 ] set_memory_rox() can fail, leaving memory unprotected. Check return and bail out when bpf_jit_binary_lock_ro() returns an error. Link: https://github.com/KSPP/linux/issues/7 Signed-off-by: Christophe Leroy Cc: linux-hardening@vger.kernel.org Reviewed-by: Kees Cook Reviewed-by: Puranjay Mohan Reviewed-by: Ilya Leoshkevich # s390x Acked-by: Tiezhu Yang # LoongArch Reviewed-by: Johan Almbladh # MIPS Part Message-ID: <036b6393f23a2032ce75a1c92220b2afcb798d5d.1709850515.git.christophe.leroy@csgroup.eu> Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

bpf: Take return from set_memory_ro() into account with bpf_prog_lock_ro()

2024-07-05T07:33:49+00:00

[ Upstream commit 7d2cc63eca0c993c99d18893214abf8f85d566d8 ] set_memory_ro() can fail, leaving memory unprotected. Check its return and take it into account as an error. Link: https://github.com/KSPP/linux/issues/7 Signed-off-by: Christophe Leroy Cc: linux-hardening@vger.kernel.org Reviewed-by: Kees Cook Message-ID: <286def78955e04382b227cb3e4b6ba272a7442e3.1709850515.git.christophe.leroy@csgroup.eu> Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

bpf: Mark bpf_spin_{lock,unlock}() helpers with notrace correctly

2024-03-26T22:19:29+00:00

[ Upstream commit 178c54666f9c4d2f49f2ea661d0c11b52f0ed190 ] Currently tracing is supposed not to allow for bpf_spin_{lock,unlock}() helper calls. This is to prevent deadlock for the following cases: - there is a prog (prog-A) calling bpf_spin_{lock,unlock}(). - there is a tracing program (prog-B), e.g., fentry, attached to bpf_spin_lock() and/or bpf_spin_unlock(). - prog-B calls bpf_spin_{lock,unlock}(). For such a case, when prog-A calls bpf_spin_{lock,unlock}(), a deadlock will happen. The related source codes are below in kernel/bpf/helpers.c: notrace BPF_CALL_1(bpf_spin_lock, struct bpf_spin_lock *, lock) notrace BPF_CALL_1(bpf_spin_unlock, struct bpf_spin_lock *, lock) notrace is supposed to prevent fentry prog from attaching to bpf_spin_{lock,unlock}(). But actually this is not the case and fentry prog can successfully attached to bpf_spin_lock(). Siddharth Chintamaneni reported the issue in [1]. The following is the macro definition for above BPF_CALL_1: #define BPF_CALL_x(x, name, ...) \ static __always_inline \ u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)); \ typedef u64 (*btf_##name)(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)); \ u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)); \ u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)) \ { \ return ((btf_##name)____##name)(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\ } \ static __always_inline \ u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)) #define BPF_CALL_1(name, ...) BPF_CALL_x(1, name, __VA_ARGS__) The notrace attribute is actually applied to the static always_inline function ____bpf_spin_{lock,unlock}(). The actual callback function bpf_spin_{lock,unlock}() is not marked with notrace, hence allowing fentry prog to attach to two helpers, and this may cause the above mentioned deadlock. Siddharth Chintamaneni actually has a reproducer in [2]. To fix the issue, a new macro NOTRACE_BPF_CALL_1 is introduced which will add notrace attribute to the original function instead of the hidden always_inline function and this fixed the problem. [1] https://lore.kernel.org/bpf/CAE5sdEigPnoGrzN8WU7Tx-h-iFuMZgW06qp0KHWtpvoXxf1OAQ@mail.gmail.com/ [2] https://lore.kernel.org/bpf/CAE5sdEg6yUc_Jz50AnUXEEUh6O73yQ1Z6NV2srJnef0ZrQkZew@mail.gmail.com/ Fixes: d83525ca62cf ("bpf: introduce bpf_spin_lock") Signed-off-by: Yonghong Song Signed-off-by: Andrii Nakryiko Acked-by: Jiri Olsa Link: https://lore.kernel.org/bpf/20240207070102.335167-1-yonghong.song@linux.dev Signed-off-by: Sasha Levin