From: Kumar Kartikeya Dwivedi <memxor@gmail.com> stable inclusion from stable-v6.6.160 commit 9496d857205e60241034b798d7745ff8830ba599 category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/10219 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit d05524794240b52fdc3b6c1220dd05505715824d ] bpf_sys_bpf() executes the bpf(2) syscall body, which can take mutexes, allocate with GFP_KERNEL, and wait for an RCU grace period. bpf_sys_close() reaches close_fd() and filp_close(), which can sleep as well. Both helpers are limited to BPF_PROG_TYPE_SYSCALL, whose main program is sleepable. That does not make every callback sleepable: a syscall program can register a bpf_timer callback, and the verifier checks that callback in a non-sleepable context while retaining the syscall helper set. Without .might_sleep on the prototypes, such a callback can invoke bpf_sys_bpf() from hrtimer softirq context and trigger a scheduling-while-atomic failure. bpf_sys_close() is exposed through the same missing context check. Set .might_sleep on both prototypes so the existing helper-context check rejects them from timer callbacks and other atomic regions. Calls from the sleepable main body remain valid. Fixes: 79a7f8bdb159 ("bpf: Introduce bpf_sys_bpf() helper and program type.") Fixes: 3abea089246f ("bpf: Add bpf_sys_close() helper.") Reported-by: Nicholas Carlini <npc@anthropic.com> Suggested-by: Nicholas Carlini <npc@anthropic.com> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20260903144433.1716731-10-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Pu Lehui <pulehui@huawei.com> --- kernel/bpf/syscall.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index ff1c8dc903cb..b18ac538fd87 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -5814,6 +5814,7 @@ EXPORT_SYMBOL(kern_sys_bpf); static const struct bpf_func_proto bpf_sys_bpf_proto = { .func = bpf_sys_bpf, .gpl_only = false, + .might_sleep = true, .ret_type = RET_INTEGER, .arg1_type = ARG_ANYTHING, .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, @@ -5839,6 +5840,7 @@ BPF_CALL_1(bpf_sys_close, u32, fd) static const struct bpf_func_proto bpf_sys_close_proto = { .func = bpf_sys_close, .gpl_only = false, + .might_sleep = true, .ret_type = RET_INTEGER, .arg1_type = ARG_ANYTHING, }; -- 2.34.1