linux-stable.git/include/linux/filter.h, branch v5.15.208 Linux kernel stable tree bpf: Add bpf_prog_run_data_pointers() 2025-12-06T21:09:29+00:00 Eric Dumazet edumazet@google.com 2025-11-12T12:55:16+00:00 c4cdd143c35974a2cedd000fa9eb3accc3023b20 [ 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 <syzkaller@googlegroups.com> Closes: https://lore.kernel.org/netdev/6913437c.a70a0220.22f260.013b.GAE@google.com/ Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Reviewed-by: Victor Nogueira <victor@mojatatu.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Link: https://patch.msgid.link/20251112125516.1563021-1-edumazet@google.com Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ 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 <syzkaller@googlegroups.com>
Closes: https://lore.kernel.org/netdev/6913437c.a70a0220.22f260.013b.GAE@google.com/
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20251112125516.1563021-1-edumazet@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
bpf: Don't use %pK through printk 2025-12-06T21:09:16+00:00 Thomas Weißschuh thomas.weissschuh@linutronix.de 2025-08-11T12:08:04+00:00 13ce905f0777d07780e2f34401715a0e4241a42b [ 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 <thomas.weissschuh@linutronix.de> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20250811-restricted-pointers-bpf-v1-1-a1d7cc3cb9e7@linutronix.de Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ 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 <thomas.weissschuh@linutronix.de>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250811-restricted-pointers-bpf-v1-1-a1d7cc3cb9e7@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
xdp: Reset bpf_redirect_info before running a xdp's BPF prog. 2025-05-02T05:44:39+00:00 Sebastian Andrzej Siewior bigeasy@linutronix.de 2025-04-24T13:03:14+00:00 c82ca029b29fd7744cbadc9b5b4038b344d7b03f Ricardo reported a KASAN discovered use after free in v6.6-stable. The syzbot starts a BPF program via xdp_test_run_batch() which assigns ri->tgt_value via dev_hash_map_redirect() and the return code isn't XDP_REDIRECT it looks like nonsense. So the output in bpf_warn_invalid_xdp_action() appears once. Then the TUN driver runs another BPF program (on the same CPU) which returns XDP_REDIRECT without setting ri->tgt_value first. It invokes bpf_trace_printk() to print four characters and obtain the required return value. This is enough to get xdp_do_redirect() invoked which then accesses the pointer in tgt_value which might have been already deallocated. This problem does not affect upstream because since commit 401cb7dae8130 ("net: Reference bpf_redirect_info via task_struct on PREEMPT_RT.") the per-CPU variable is referenced via task's task_struct and exists on the stack during NAPI callback. Therefore it is cleared once before the first invocation and remains valid within the RCU section of the NAPI callback. Instead of performing the huge backport of the commit (plus its fix ups) here is an alternative version which only resets the variable in question prior invoking the BPF program. Acked-by: Toke Høiland-Jørgensen <toke@kernel.org> Reported-by: Ricardo Cañuelo Navarro <rcn@igalia.com> Closes: https://lore.kernel.org/all/20250226-20250204-kasan-slab-use-after-free-read-in-dev_map_enqueue__submit-v3-0-360efec441ba@igalia.com/ Fixes: 97f91a7cf04ff ("bpf: add bpf_redirect_map helper routine") Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Ricardo reported a KASAN discovered use after free in v6.6-stable.

The syzbot starts a BPF program via xdp_test_run_batch() which assigns
ri->tgt_value via dev_hash_map_redirect() and the return code isn't
XDP_REDIRECT it looks like nonsense. So the output in
bpf_warn_invalid_xdp_action() appears once.
Then the TUN driver runs another BPF program (on the same CPU) which
returns XDP_REDIRECT without setting ri->tgt_value first. It invokes
bpf_trace_printk() to print four characters and obtain the required
return value. This is enough to get xdp_do_redirect() invoked which
then accesses the pointer in tgt_value which might have been already
deallocated.

This problem does not affect upstream because since commit
	401cb7dae8130 ("net: Reference bpf_redirect_info via task_struct on PREEMPT_RT.")

the per-CPU variable is referenced via task's task_struct and exists on
the stack during NAPI callback. Therefore it is cleared once before the
first invocation and remains valid within the RCU section of the NAPI
callback.

Instead of performing the huge backport of the commit (plus its fix ups)
here is an alternative version which only resets the variable in
question prior invoking the BPF program.

Acked-by: Toke Høiland-Jørgensen <toke@kernel.org>
Reported-by: Ricardo Cañuelo Navarro <rcn@igalia.com>
Closes: https://lore.kernel.org/all/20250226-20250204-kasan-slab-use-after-free-read-in-dev_map_enqueue__submit-v3-0-360efec441ba@igalia.com/
Fixes: 97f91a7cf04ff ("bpf: add bpf_redirect_map helper routine")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bpf: Take return from set_memory_ro() into account with bpf_prog_lock_ro() 2024-07-05T07:14:42+00:00 Christophe Leroy christophe.leroy@csgroup.eu 2024-03-08T05:38:07+00:00 a359696856ca9409fb97655c5a8ef0f549cb6e03 [ 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 <christophe.leroy@csgroup.eu> Cc: linux-hardening@vger.kernel.org <linux-hardening@vger.kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Message-ID: <286def78955e04382b227cb3e4b6ba272a7442e3.1709850515.git.christophe.leroy@csgroup.eu> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ 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 <christophe.leroy@csgroup.eu>
Cc: linux-hardening@vger.kernel.org <linux-hardening@vger.kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Message-ID: <286def78955e04382b227cb3e4b6ba272a7442e3.1709850515.git.christophe.leroy@csgroup.eu>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
xdp: Add xdp_do_redirect_frame() for pre-computed xdp_frames 2024-05-17T09:50:47+00:00 Toke Høiland-Jørgensen toke@redhat.com 2022-01-03T15:08:10+00:00 b6a7077c0ffee7e3a709f2606924e4dd954ad966 [ Upstream commit 1372d34ccf6dd480332b2bcb2fd59a2b9a0df415 ] Add an xdp_do_redirect_frame() variant which supports pre-computed xdp_frame structures. This will be used in bpf_prog_run() to avoid having to write to the xdp_frame structure when the XDP program doesn't modify the frame boundaries. Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220103150812.87914-6-toke@redhat.com Stable-dep-of: 5bcf0dcbf906 ("xdp: use flags field to disambiguate broadcast redirect") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 1372d34ccf6dd480332b2bcb2fd59a2b9a0df415 ]

Add an xdp_do_redirect_frame() variant which supports pre-computed
xdp_frame structures. This will be used in bpf_prog_run() to avoid having
to write to the xdp_frame structure when the XDP program doesn't modify the
frame boundaries.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220103150812.87914-6-toke@redhat.com
Stable-dep-of: 5bcf0dcbf906 ("xdp: use flags field to disambiguate broadcast redirect")
Signed-off-by: Sasha Levin <sashal@kernel.org>
bpf: net: Change sk_getsockopt() to take the sockptr_t argument 2024-03-26T22:21:23+00:00 Martin KaFai Lau martin.lau@kernel.org 2022-09-02T00:28:02+00:00 07aa35a50fe68845a37ff9ae663ac509fe9d3205 [ Upstream commit 4ff09db1b79b98b4a2a7511571c640b76cab3beb ] This patch changes sk_getsockopt() to take the sockptr_t argument such that it can be used by bpf_getsockopt(SOL_SOCKET) in a latter patch. security_socket_getpeersec_stream() is not changed. It stays with the __user ptr (optval.user and optlen.user) to avoid changes to other security hooks. bpf_getsockopt(SOL_SOCKET) also does not support SO_PEERSEC. Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20220902002802.2888419-1-kafai@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Stable-dep-of: 5c3be3e0eb44 ("ipmr: fix incorrect parameter validation in the ip_mroute_getsockopt() function") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 4ff09db1b79b98b4a2a7511571c640b76cab3beb ]

This patch changes sk_getsockopt() to take the sockptr_t argument
such that it can be used by bpf_getsockopt(SOL_SOCKET) in a
latter patch.

security_socket_getpeersec_stream() is not changed.  It stays
with the __user ptr (optval.user and optlen.user) to avoid changes
to other security hooks.  bpf_getsockopt(SOL_SOCKET) also does not
support SO_PEERSEC.

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20220902002802.2888419-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Stable-dep-of: 5c3be3e0eb44 ("ipmr: fix incorrect parameter validation in the ip_mroute_getsockopt() function")
Signed-off-by: Sasha Levin <sashal@kernel.org>
bpf: Mark bpf_spin_{lock,unlock}() helpers with notrace correctly 2024-03-26T22:21:19+00:00 Yonghong Song yonghong.song@linux.dev 2024-02-07T07:01:02+00:00 487eff913ea92643a3324c94dfa76cf3715f8835 [ 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 <yonghong.song@linux.dev> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/bpf/20240207070102.335167-1-yonghong.song@linux.dev Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ 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 <yonghong.song@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20240207070102.335167-1-yonghong.song@linux.dev
Signed-off-by: Sasha Levin <sashal@kernel.org>
bpf: Use u64_stats_t in struct bpf_prog_stats 2022-03-08T18:12:40+00:00 Eric Dumazet edumazet@google.com 2021-10-26T21:41:33+00:00 aa5040691cb761a04c206a893e5771a904d22ab7 [ Upstream commit 61a0abaee2092eee69e44fe60336aa2f5b578938 ] Commit 316580b69d0a ("u64_stats: provide u64_stats_t type") fixed possible load/store tearing on 64bit arches. For instance the following C code stats->nsecs += sched_clock() - start; Could be rightfully implemented like this by a compiler, confusing concurrent readers a lot: stats->nsecs += sched_clock(); // arbitrary delay stats->nsecs -= start; Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211026214133.3114279-4-eric.dumazet@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 61a0abaee2092eee69e44fe60336aa2f5b578938 ]

Commit 316580b69d0a ("u64_stats: provide u64_stats_t type")
fixed possible load/store tearing on 64bit arches.

For instance the following C code

stats->nsecs += sched_clock() - start;

Could be rightfully implemented like this by a compiler,
confusing concurrent readers a lot:

stats->nsecs += sched_clock();
// arbitrary delay
stats->nsecs -= start;

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211026214133.3114279-4-eric.dumazet@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
bpf: Make sure bpf_disable_instrumentation() is safe vs preemption. 2021-12-14T09:57:09+00:00 Sebastian Andrzej Siewior bigeasy@linutronix.de 2021-11-27T16:32:00+00:00 e76da2e8a09a4ee289e0e90e61092f84feaeb120 commit 79364031c5b4365ca28ac0fa00acfab5bf465be1 upstream. The initial implementation of migrate_disable() for mainline was a wrapper around preempt_disable(). RT kernels substituted this with a real migrate disable implementation. Later on mainline gained true migrate disable support, but neither documentation nor affected code were updated. Remove stale comments claiming that migrate_disable() is PREEMPT_RT only. Don't use __this_cpu_inc() in the !PREEMPT_RT path because preemption is not disabled and the RMW operation can be preempted. Fixes: 74d862b682f51 ("sched: Make migrate_disable/enable() independent of RT") Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20211127163200.10466-3-bigeasy@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 79364031c5b4365ca28ac0fa00acfab5bf465be1 upstream.

The initial implementation of migrate_disable() for mainline was a
wrapper around preempt_disable(). RT kernels substituted this with a
real migrate disable implementation.

Later on mainline gained true migrate disable support, but neither
documentation nor affected code were updated.

Remove stale comments claiming that migrate_disable() is PREEMPT_RT only.

Don't use __this_cpu_inc() in the !PREEMPT_RT path because preemption is
not disabled and the RMW operation can be preempted.

Fixes: 74d862b682f51 ("sched: Make migrate_disable/enable() independent of RT")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211127163200.10466-3-bigeasy@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bpf: Avoid races in __bpf_prog_run() for 32bit arches 2021-11-18T18:16:42+00:00 Eric Dumazet edumazet@google.com 2021-10-26T21:41:31+00:00 ae1fffdf3b95d7ef2dbcc5aeab80db2a2ce06cb5 [ Upstream commit f941eadd8d6d4ee2f8c9aeab8e1da5e647533a7d ] __bpf_prog_run() can run from non IRQ contexts, meaning it could be re entered if interrupted. This calls for the irq safe variant of u64_stats_update_{begin|end}, or risk a deadlock. This patch is a nop on 64bit arches, fortunately. syzbot report: WARNING: inconsistent lock state 5.12.0-rc3-syzkaller #0 Not tainted -------------------------------- inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. udevd/4013 [HC0[0]:SC0[0]:HE1:SE1] takes: ff7c9dec (&(&pstats->syncp)->seq){+.?.}-{0:0}, at: sk_filter include/linux/filter.h:867 [inline] ff7c9dec (&(&pstats->syncp)->seq){+.?.}-{0:0}, at: do_one_broadcast net/netlink/af_netlink.c:1468 [inline] ff7c9dec (&(&pstats->syncp)->seq){+.?.}-{0:0}, at: netlink_broadcast_filtered+0x27c/0x4fc net/netlink/af_netlink.c:1520 {IN-SOFTIRQ-W} state was registered at: lock_acquire.part.0+0xf0/0x41c kernel/locking/lockdep.c:5510 lock_acquire+0x6c/0x74 kernel/locking/lockdep.c:5483 do_write_seqcount_begin_nested include/linux/seqlock.h:520 [inline] do_write_seqcount_begin include/linux/seqlock.h:545 [inline] u64_stats_update_begin include/linux/u64_stats_sync.h:129 [inline] bpf_prog_run_pin_on_cpu include/linux/filter.h:624 [inline] bpf_prog_run_clear_cb+0x1bc/0x270 include/linux/filter.h:755 run_filter+0xa0/0x17c net/packet/af_packet.c:2031 packet_rcv+0xc0/0x3e0 net/packet/af_packet.c:2104 dev_queue_xmit_nit+0x2bc/0x39c net/core/dev.c:2387 xmit_one net/core/dev.c:3588 [inline] dev_hard_start_xmit+0x94/0x518 net/core/dev.c:3609 sch_direct_xmit+0x11c/0x1f0 net/sched/sch_generic.c:313 qdisc_restart net/sched/sch_generic.c:376 [inline] __qdisc_run+0x194/0x7f8 net/sched/sch_generic.c:384 qdisc_run include/net/pkt_sched.h:136 [inline] qdisc_run include/net/pkt_sched.h:128 [inline] __dev_xmit_skb net/core/dev.c:3795 [inline] __dev_queue_xmit+0x65c/0xf84 net/core/dev.c:4150 dev_queue_xmit+0x14/0x18 net/core/dev.c:4215 neigh_resolve_output net/core/neighbour.c:1491 [inline] neigh_resolve_output+0x170/0x228 net/core/neighbour.c:1471 neigh_output include/net/neighbour.h:510 [inline] ip6_finish_output2+0x2e4/0x9fc net/ipv6/ip6_output.c:117 __ip6_finish_output net/ipv6/ip6_output.c:182 [inline] __ip6_finish_output+0x164/0x3f8 net/ipv6/ip6_output.c:161 ip6_finish_output+0x2c/0xb0 net/ipv6/ip6_output.c:192 NF_HOOK_COND include/linux/netfilter.h:290 [inline] ip6_output+0x74/0x294 net/ipv6/ip6_output.c:215 dst_output include/net/dst.h:448 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] NF_HOOK include/linux/netfilter.h:295 [inline] mld_sendpack+0x2a8/0x7e4 net/ipv6/mcast.c:1679 mld_send_cr net/ipv6/mcast.c:1975 [inline] mld_ifc_timer_expire+0x1e8/0x494 net/ipv6/mcast.c:2474 call_timer_fn+0xd0/0x570 kernel/time/timer.c:1431 expire_timers kernel/time/timer.c:1476 [inline] __run_timers kernel/time/timer.c:1745 [inline] run_timer_softirq+0x2e4/0x384 kernel/time/timer.c:1758 __do_softirq+0x204/0x7ac kernel/softirq.c:345 do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline] invoke_softirq kernel/softirq.c:228 [inline] __irq_exit_rcu+0x1d8/0x200 kernel/softirq.c:422 irq_exit+0x10/0x3c kernel/softirq.c:446 __handle_domain_irq+0xb4/0x120 kernel/irq/irqdesc.c:692 handle_domain_irq include/linux/irqdesc.h:176 [inline] gic_handle_irq+0x84/0xac drivers/irqchip/irq-gic.c:370 __irq_svc+0x5c/0x94 arch/arm/kernel/entry-armv.S:205 debug_smp_processor_id+0x0/0x24 lib/smp_processor_id.c:53 rcu_read_lock_held_common kernel/rcu/update.c:108 [inline] rcu_read_lock_sched_held+0x24/0x7c kernel/rcu/update.c:123 trace_lock_acquire+0x24c/0x278 include/trace/events/lock.h:13 lock_acquire+0x3c/0x74 kernel/locking/lockdep.c:5481 rcu_lock_acquire include/linux/rcupdate.h:267 [inline] rcu_read_lock include/linux/rcupdate.h:656 [inline] avc_has_perm_noaudit+0x6c/0x260 security/selinux/avc.c:1150 selinux_inode_permission+0x140/0x220 security/selinux/hooks.c:3141 security_inode_permission+0x44/0x60 security/security.c:1268 inode_permission.part.0+0x5c/0x13c fs/namei.c:521 inode_permission fs/namei.c:494 [inline] may_lookup fs/namei.c:1652 [inline] link_path_walk.part.0+0xd4/0x38c fs/namei.c:2208 link_path_walk fs/namei.c:2189 [inline] path_lookupat+0x3c/0x1b8 fs/namei.c:2419 filename_lookup+0xa8/0x1a4 fs/namei.c:2453 user_path_at_empty+0x74/0x90 fs/namei.c:2733 do_readlinkat+0x5c/0x12c fs/stat.c:417 __do_sys_readlink fs/stat.c:450 [inline] sys_readlink+0x24/0x28 fs/stat.c:447 ret_fast_syscall+0x0/0x2c arch/arm/mm/proc-v7.S:64 0x7eaa4974 irq event stamp: 298277 hardirqs last enabled at (298277): [<802000d0>] no_work_pending+0x4/0x34 hardirqs last disabled at (298276): [<8020c9b8>] do_work_pending+0x9c/0x648 arch/arm/kernel/signal.c:676 softirqs last enabled at (298216): [<8020167c>] __do_softirq+0x584/0x7ac kernel/softirq.c:372 softirqs last disabled at (298201): [<8024dff4>] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline] softirqs last disabled at (298201): [<8024dff4>] invoke_softirq kernel/softirq.c:228 [inline] softirqs last disabled at (298201): [<8024dff4>] __irq_exit_rcu+0x1d8/0x200 kernel/softirq.c:422 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&pstats->syncp)->seq); <Interrupt> lock(&(&pstats->syncp)->seq); *** DEADLOCK *** 1 lock held by udevd/4013: #0: 82b09c5c (rcu_read_lock){....}-{1:2}, at: sk_filter_trim_cap+0x54/0x434 net/core/filter.c:139 stack backtrace: CPU: 1 PID: 4013 Comm: udevd Not tainted 5.12.0-rc3-syzkaller #0 Hardware name: ARM-Versatile Express Backtrace: [<81802550>] (dump_backtrace) from [<818027c4>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:252) r7:00000080 r6:600d0093 r5:00000000 r4:82b58344 [<818027ac>] (show_stack) from [<81809e98>] (__dump_stack lib/dump_stack.c:79 [inline]) [<818027ac>] (show_stack) from [<81809e98>] (dump_stack+0xb8/0xe8 lib/dump_stack.c:120) [<81809de0>] (dump_stack) from [<81804a00>] (print_usage_bug.part.0+0x228/0x230 kernel/locking/lockdep.c:3806) r7:86bcb768 r6:81a0326c r5:830f96a8 r4:86bcb0c0 [<818047d8>] (print_usage_bug.part.0) from [<802bb1b8>] (print_usage_bug kernel/locking/lockdep.c:3776 [inline]) [<818047d8>] (print_usage_bug.part.0) from [<802bb1b8>] (valid_state kernel/locking/lockdep.c:3818 [inline]) [<818047d8>] (print_usage_bug.part.0) from [<802bb1b8>] (mark_lock_irq kernel/locking/lockdep.c:4021 [inline]) [<818047d8>] (print_usage_bug.part.0) from [<802bb1b8>] (mark_lock.part.0+0xc34/0x136c kernel/locking/lockdep.c:4478) r10:83278fe8 r9:82c6d748 r8:00000000 r7:82c6d2d4 r6:00000004 r5:86bcb768 r4:00000006 [<802ba584>] (mark_lock.part.0) from [<802bc644>] (mark_lock kernel/locking/lockdep.c:4442 [inline]) [<802ba584>] (mark_lock.part.0) from [<802bc644>] (mark_usage kernel/locking/lockdep.c:4391 [inline]) [<802ba584>] (mark_lock.part.0) from [<802bc644>] (__lock_acquire+0x9bc/0x3318 kernel/locking/lockdep.c:4854) r10:86bcb768 r9:86bcb0c0 r8:00000001 r7:00040000 r6:0000075a r5:830f96a8 r4:00000000 [<802bbc88>] (__lock_acquire) from [<802bfb90>] (lock_acquire.part.0+0xf0/0x41c kernel/locking/lockdep.c:5510) r10:00000000 r9:600d0013 r8:00000000 r7:00000000 r6:828a2680 r5:828a2680 r4:861e5bc8 [<802bfaa0>] (lock_acquire.part.0) from [<802bff28>] (lock_acquire+0x6c/0x74 kernel/locking/lockdep.c:5483) r10:8146137c r9:00000000 r8:00000001 r7:00000000 r6:00000000 r5:00000000 r4:ff7c9dec [<802bfebc>] (lock_acquire) from [<81381eb4>] (do_write_seqcount_begin_nested include/linux/seqlock.h:520 [inline]) [<802bfebc>] (lock_acquire) from [<81381eb4>] (do_write_seqcount_begin include/linux/seqlock.h:545 [inline]) [<802bfebc>] (lock_acquire) from [<81381eb4>] (u64_stats_update_begin include/linux/u64_stats_sync.h:129 [inline]) [<802bfebc>] (lock_acquire) from [<81381eb4>] (__bpf_prog_run_save_cb include/linux/filter.h:727 [inline]) [<802bfebc>] (lock_acquire) from [<81381eb4>] (bpf_prog_run_save_cb include/linux/filter.h:741 [inline]) [<802bfebc>] (lock_acquire) from [<81381eb4>] (sk_filter_trim_cap+0x26c/0x434 net/core/filter.c:149) r10:a4095dd0 r9:ff7c9dd0 r8:e44be000 r7:8146137c r6:00000001 r5:8611ba80 r4:00000000 [<81381c48>] (sk_filter_trim_cap) from [<8146137c>] (sk_filter include/linux/filter.h:867 [inline]) [<81381c48>] (sk_filter_trim_cap) from [<8146137c>] (do_one_broadcast net/netlink/af_netlink.c:1468 [inline]) [<81381c48>] (sk_filter_trim_cap) from [<8146137c>] (netlink_broadcast_filtered+0x27c/0x4fc net/netlink/af_netlink.c:1520) r10:00000001 r9:833d6b1c r8:00000000 r7:8572f864 r6:8611ba80 r5:8698d800 r4:8572f800 [<81461100>] (netlink_broadcast_filtered) from [<81463e60>] (netlink_broadcast net/netlink/af_netlink.c:1544 [inline]) [<81461100>] (netlink_broadcast_filtered) from [<81463e60>] (netlink_sendmsg+0x3d0/0x478 net/netlink/af_netlink.c:1925) r10:00000000 r9:00000002 r8:8698d800 r7:000000b7 r6:8611b900 r5:861e5f50 r4:86aa3000 [<81463a90>] (netlink_sendmsg) from [<81321f54>] (sock_sendmsg_nosec net/socket.c:654 [inline]) [<81463a90>] (netlink_sendmsg) from [<81321f54>] (sock_sendmsg+0x3c/0x4c net/socket.c:674) r10:00000000 r9:861e5dd4 r8:00000000 r7:86570000 r6:00000000 r5:86570000 r4:861e5f50 [<81321f18>] (sock_sendmsg) from [<813234d0>] (____sys_sendmsg+0x230/0x29c net/socket.c:2350) r5:00000040 r4:861e5f50 [<813232a0>] (____sys_sendmsg) from [<8132549c>] (___sys_sendmsg+0xac/0xe4 net/socket.c:2404) r10:00000128 r9:861e4000 r8:00000000 r7:00000000 r6:86570000 r5:861e5f50 r4:00000000 [<813253f0>] (___sys_sendmsg) from [<81325684>] (__sys_sendmsg net/socket.c:2433 [inline]) [<813253f0>] (___sys_sendmsg) from [<81325684>] (__do_sys_sendmsg net/socket.c:2442 [inline]) [<813253f0>] (___sys_sendmsg) from [<81325684>] (sys_sendmsg+0x58/0xa0 net/socket.c:2440) r8:80200224 r7:00000128 r6:00000000 r5:7eaa541c r4:86570000 [<8132562c>] (sys_sendmsg) from [<80200060>] (ret_fast_syscall+0x0/0x2c arch/arm/mm/proc-v7.S:64) Exception stack(0x861e5fa8 to 0x861e5ff0) 5fa0: 00000000 00000000 0000000c 7eaa541c 00000000 00000000 5fc0: 00000000 00000000 76fbf840 00000128 00000000 0000008f 7eaa541c 000563f8 5fe0: 00056110 7eaa53e0 00036cec 76c9bf44 r6:76fbf840 r5:00000000 r4:00000000 Fixes: 492ecee892c2 ("bpf: enable program stats") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211026214133.3114279-2-eric.dumazet@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit f941eadd8d6d4ee2f8c9aeab8e1da5e647533a7d ]

__bpf_prog_run() can run from non IRQ contexts, meaning
it could be re entered if interrupted.

This calls for the irq safe variant of u64_stats_update_{begin|end},
or risk a deadlock.

This patch is a nop on 64bit arches, fortunately.

syzbot report:

WARNING: inconsistent lock state
5.12.0-rc3-syzkaller #0 Not tainted
--------------------------------
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
udevd/4013 [HC0[0]:SC0[0]:HE1:SE1] takes:
ff7c9dec (&(&pstats->syncp)->seq){+.?.}-{0:0}, at: sk_filter include/linux/filter.h:867 [inline]
ff7c9dec (&(&pstats->syncp)->seq){+.?.}-{0:0}, at: do_one_broadcast net/netlink/af_netlink.c:1468 [inline]
ff7c9dec (&(&pstats->syncp)->seq){+.?.}-{0:0}, at: netlink_broadcast_filtered+0x27c/0x4fc net/netlink/af_netlink.c:1520
{IN-SOFTIRQ-W} state was registered at:
  lock_acquire.part.0+0xf0/0x41c kernel/locking/lockdep.c:5510
  lock_acquire+0x6c/0x74 kernel/locking/lockdep.c:5483
  do_write_seqcount_begin_nested include/linux/seqlock.h:520 [inline]
  do_write_seqcount_begin include/linux/seqlock.h:545 [inline]
  u64_stats_update_begin include/linux/u64_stats_sync.h:129 [inline]
  bpf_prog_run_pin_on_cpu include/linux/filter.h:624 [inline]
  bpf_prog_run_clear_cb+0x1bc/0x270 include/linux/filter.h:755
  run_filter+0xa0/0x17c net/packet/af_packet.c:2031
  packet_rcv+0xc0/0x3e0 net/packet/af_packet.c:2104
  dev_queue_xmit_nit+0x2bc/0x39c net/core/dev.c:2387
  xmit_one net/core/dev.c:3588 [inline]
  dev_hard_start_xmit+0x94/0x518 net/core/dev.c:3609
  sch_direct_xmit+0x11c/0x1f0 net/sched/sch_generic.c:313
  qdisc_restart net/sched/sch_generic.c:376 [inline]
  __qdisc_run+0x194/0x7f8 net/sched/sch_generic.c:384
  qdisc_run include/net/pkt_sched.h:136 [inline]
  qdisc_run include/net/pkt_sched.h:128 [inline]
  __dev_xmit_skb net/core/dev.c:3795 [inline]
  __dev_queue_xmit+0x65c/0xf84 net/core/dev.c:4150
  dev_queue_xmit+0x14/0x18 net/core/dev.c:4215
  neigh_resolve_output net/core/neighbour.c:1491 [inline]
  neigh_resolve_output+0x170/0x228 net/core/neighbour.c:1471
  neigh_output include/net/neighbour.h:510 [inline]
  ip6_finish_output2+0x2e4/0x9fc net/ipv6/ip6_output.c:117
  __ip6_finish_output net/ipv6/ip6_output.c:182 [inline]
  __ip6_finish_output+0x164/0x3f8 net/ipv6/ip6_output.c:161
  ip6_finish_output+0x2c/0xb0 net/ipv6/ip6_output.c:192
  NF_HOOK_COND include/linux/netfilter.h:290 [inline]
  ip6_output+0x74/0x294 net/ipv6/ip6_output.c:215
  dst_output include/net/dst.h:448 [inline]
  NF_HOOK include/linux/netfilter.h:301 [inline]
  NF_HOOK include/linux/netfilter.h:295 [inline]
  mld_sendpack+0x2a8/0x7e4 net/ipv6/mcast.c:1679
  mld_send_cr net/ipv6/mcast.c:1975 [inline]
  mld_ifc_timer_expire+0x1e8/0x494 net/ipv6/mcast.c:2474
  call_timer_fn+0xd0/0x570 kernel/time/timer.c:1431
  expire_timers kernel/time/timer.c:1476 [inline]
  __run_timers kernel/time/timer.c:1745 [inline]
  run_timer_softirq+0x2e4/0x384 kernel/time/timer.c:1758
  __do_softirq+0x204/0x7ac kernel/softirq.c:345
  do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline]
  invoke_softirq kernel/softirq.c:228 [inline]
  __irq_exit_rcu+0x1d8/0x200 kernel/softirq.c:422
  irq_exit+0x10/0x3c kernel/softirq.c:446
  __handle_domain_irq+0xb4/0x120 kernel/irq/irqdesc.c:692
  handle_domain_irq include/linux/irqdesc.h:176 [inline]
  gic_handle_irq+0x84/0xac drivers/irqchip/irq-gic.c:370
  __irq_svc+0x5c/0x94 arch/arm/kernel/entry-armv.S:205
  debug_smp_processor_id+0x0/0x24 lib/smp_processor_id.c:53
  rcu_read_lock_held_common kernel/rcu/update.c:108 [inline]
  rcu_read_lock_sched_held+0x24/0x7c kernel/rcu/update.c:123
  trace_lock_acquire+0x24c/0x278 include/trace/events/lock.h:13
  lock_acquire+0x3c/0x74 kernel/locking/lockdep.c:5481
  rcu_lock_acquire include/linux/rcupdate.h:267 [inline]
  rcu_read_lock include/linux/rcupdate.h:656 [inline]
  avc_has_perm_noaudit+0x6c/0x260 security/selinux/avc.c:1150
  selinux_inode_permission+0x140/0x220 security/selinux/hooks.c:3141
  security_inode_permission+0x44/0x60 security/security.c:1268
  inode_permission.part.0+0x5c/0x13c fs/namei.c:521
  inode_permission fs/namei.c:494 [inline]
  may_lookup fs/namei.c:1652 [inline]
  link_path_walk.part.0+0xd4/0x38c fs/namei.c:2208
  link_path_walk fs/namei.c:2189 [inline]
  path_lookupat+0x3c/0x1b8 fs/namei.c:2419
  filename_lookup+0xa8/0x1a4 fs/namei.c:2453
  user_path_at_empty+0x74/0x90 fs/namei.c:2733
  do_readlinkat+0x5c/0x12c fs/stat.c:417
  __do_sys_readlink fs/stat.c:450 [inline]
  sys_readlink+0x24/0x28 fs/stat.c:447
  ret_fast_syscall+0x0/0x2c arch/arm/mm/proc-v7.S:64
  0x7eaa4974
irq event stamp: 298277
hardirqs last  enabled at (298277): [<802000d0>] no_work_pending+0x4/0x34
hardirqs last disabled at (298276): [<8020c9b8>] do_work_pending+0x9c/0x648 arch/arm/kernel/signal.c:676
softirqs last  enabled at (298216): [<8020167c>] __do_softirq+0x584/0x7ac kernel/softirq.c:372
softirqs last disabled at (298201): [<8024dff4>] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline]
softirqs last disabled at (298201): [<8024dff4>] invoke_softirq kernel/softirq.c:228 [inline]
softirqs last disabled at (298201): [<8024dff4>] __irq_exit_rcu+0x1d8/0x200 kernel/softirq.c:422

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&(&pstats->syncp)->seq);
  <Interrupt>
    lock(&(&pstats->syncp)->seq);

 *** DEADLOCK ***

1 lock held by udevd/4013:
 #0: 82b09c5c (rcu_read_lock){....}-{1:2}, at: sk_filter_trim_cap+0x54/0x434 net/core/filter.c:139

stack backtrace:
CPU: 1 PID: 4013 Comm: udevd Not tainted 5.12.0-rc3-syzkaller #0
Hardware name: ARM-Versatile Express
Backtrace:
[<81802550>] (dump_backtrace) from [<818027c4>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:252)
 r7:00000080 r6:600d0093 r5:00000000 r4:82b58344
[<818027ac>] (show_stack) from [<81809e98>] (__dump_stack lib/dump_stack.c:79 [inline])
[<818027ac>] (show_stack) from [<81809e98>] (dump_stack+0xb8/0xe8 lib/dump_stack.c:120)
[<81809de0>] (dump_stack) from [<81804a00>] (print_usage_bug.part.0+0x228/0x230 kernel/locking/lockdep.c:3806)
 r7:86bcb768 r6:81a0326c r5:830f96a8 r4:86bcb0c0
[<818047d8>] (print_usage_bug.part.0) from [<802bb1b8>] (print_usage_bug kernel/locking/lockdep.c:3776 [inline])
[<818047d8>] (print_usage_bug.part.0) from [<802bb1b8>] (valid_state kernel/locking/lockdep.c:3818 [inline])
[<818047d8>] (print_usage_bug.part.0) from [<802bb1b8>] (mark_lock_irq kernel/locking/lockdep.c:4021 [inline])
[<818047d8>] (print_usage_bug.part.0) from [<802bb1b8>] (mark_lock.part.0+0xc34/0x136c kernel/locking/lockdep.c:4478)
 r10:83278fe8 r9:82c6d748 r8:00000000 r7:82c6d2d4 r6:00000004 r5:86bcb768
 r4:00000006
[<802ba584>] (mark_lock.part.0) from [<802bc644>] (mark_lock kernel/locking/lockdep.c:4442 [inline])
[<802ba584>] (mark_lock.part.0) from [<802bc644>] (mark_usage kernel/locking/lockdep.c:4391 [inline])
[<802ba584>] (mark_lock.part.0) from [<802bc644>] (__lock_acquire+0x9bc/0x3318 kernel/locking/lockdep.c:4854)
 r10:86bcb768 r9:86bcb0c0 r8:00000001 r7:00040000 r6:0000075a r5:830f96a8
 r4:00000000
[<802bbc88>] (__lock_acquire) from [<802bfb90>] (lock_acquire.part.0+0xf0/0x41c kernel/locking/lockdep.c:5510)
 r10:00000000 r9:600d0013 r8:00000000 r7:00000000 r6:828a2680 r5:828a2680
 r4:861e5bc8
[<802bfaa0>] (lock_acquire.part.0) from [<802bff28>] (lock_acquire+0x6c/0x74 kernel/locking/lockdep.c:5483)
 r10:8146137c r9:00000000 r8:00000001 r7:00000000 r6:00000000 r5:00000000
 r4:ff7c9dec
[<802bfebc>] (lock_acquire) from [<81381eb4>] (do_write_seqcount_begin_nested include/linux/seqlock.h:520 [inline])
[<802bfebc>] (lock_acquire) from [<81381eb4>] (do_write_seqcount_begin include/linux/seqlock.h:545 [inline])
[<802bfebc>] (lock_acquire) from [<81381eb4>] (u64_stats_update_begin include/linux/u64_stats_sync.h:129 [inline])
[<802bfebc>] (lock_acquire) from [<81381eb4>] (__bpf_prog_run_save_cb include/linux/filter.h:727 [inline])
[<802bfebc>] (lock_acquire) from [<81381eb4>] (bpf_prog_run_save_cb include/linux/filter.h:741 [inline])
[<802bfebc>] (lock_acquire) from [<81381eb4>] (sk_filter_trim_cap+0x26c/0x434 net/core/filter.c:149)
 r10:a4095dd0 r9:ff7c9dd0 r8:e44be000 r7:8146137c r6:00000001 r5:8611ba80
 r4:00000000
[<81381c48>] (sk_filter_trim_cap) from [<8146137c>] (sk_filter include/linux/filter.h:867 [inline])
[<81381c48>] (sk_filter_trim_cap) from [<8146137c>] (do_one_broadcast net/netlink/af_netlink.c:1468 [inline])
[<81381c48>] (sk_filter_trim_cap) from [<8146137c>] (netlink_broadcast_filtered+0x27c/0x4fc net/netlink/af_netlink.c:1520)
 r10:00000001 r9:833d6b1c r8:00000000 r7:8572f864 r6:8611ba80 r5:8698d800
 r4:8572f800
[<81461100>] (netlink_broadcast_filtered) from [<81463e60>] (netlink_broadcast net/netlink/af_netlink.c:1544 [inline])
[<81461100>] (netlink_broadcast_filtered) from [<81463e60>] (netlink_sendmsg+0x3d0/0x478 net/netlink/af_netlink.c:1925)
 r10:00000000 r9:00000002 r8:8698d800 r7:000000b7 r6:8611b900 r5:861e5f50
 r4:86aa3000
[<81463a90>] (netlink_sendmsg) from [<81321f54>] (sock_sendmsg_nosec net/socket.c:654 [inline])
[<81463a90>] (netlink_sendmsg) from [<81321f54>] (sock_sendmsg+0x3c/0x4c net/socket.c:674)
 r10:00000000 r9:861e5dd4 r8:00000000 r7:86570000 r6:00000000 r5:86570000
 r4:861e5f50
[<81321f18>] (sock_sendmsg) from [<813234d0>] (____sys_sendmsg+0x230/0x29c net/socket.c:2350)
 r5:00000040 r4:861e5f50
[<813232a0>] (____sys_sendmsg) from [<8132549c>] (___sys_sendmsg+0xac/0xe4 net/socket.c:2404)
 r10:00000128 r9:861e4000 r8:00000000 r7:00000000 r6:86570000 r5:861e5f50
 r4:00000000
[<813253f0>] (___sys_sendmsg) from [<81325684>] (__sys_sendmsg net/socket.c:2433 [inline])
[<813253f0>] (___sys_sendmsg) from [<81325684>] (__do_sys_sendmsg net/socket.c:2442 [inline])
[<813253f0>] (___sys_sendmsg) from [<81325684>] (sys_sendmsg+0x58/0xa0 net/socket.c:2440)
 r8:80200224 r7:00000128 r6:00000000 r5:7eaa541c r4:86570000
[<8132562c>] (sys_sendmsg) from [<80200060>] (ret_fast_syscall+0x0/0x2c arch/arm/mm/proc-v7.S:64)
Exception stack(0x861e5fa8 to 0x861e5ff0)
5fa0:                   00000000 00000000 0000000c 7eaa541c 00000000 00000000
5fc0: 00000000 00000000 76fbf840 00000128 00000000 0000008f 7eaa541c 000563f8
5fe0: 00056110 7eaa53e0 00036cec 76c9bf44
 r6:76fbf840 r5:00000000 r4:00000000

Fixes: 492ecee892c2 ("bpf: enable program stats")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211026214133.3114279-2-eric.dumazet@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>