diff options
| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2023-08-30 10:04:04 +0200 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2023-09-06 10:39:31 +0200 |
| commit | 7645629f7dc88cd777f98970134bf1a54c8d77e3 (patch) | |
| tree | dde5b29cdd03e8b33e1e902e4b7d1f538786d17b /kernel/bpf/syscall.c | |
| parent | a454d84ee20baf7bd7be90721b9821f73c7d23d9 (diff) | |
bpf: Invoke __bpf_prog_exit_sleepable_recur() on recursion in kern_sys_bpf().
If __bpf_prog_enter_sleepable_recur() detects recursion then it returns
0 without undoing rcu_read_lock_trace(), migrate_disable() or
decrementing the recursion counter. This is fine in the JIT case because
the JIT code will jump in the 0 case to the end and invoke the matching
exit trampoline (__bpf_prog_exit_sleepable_recur()).
This is not the case in kern_sys_bpf() which returns directly to the
caller with an error code.
Add __bpf_prog_exit_sleepable_recur() as clean up in the recursion case.
Fixes: b1d18a7574d0d ("bpf: Extend sys_bpf commands for bpf_syscall programs.")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20230830080405.251926-2-bigeasy@linutronix.de
Diffstat (limited to 'kernel/bpf/syscall.c')
| -rw-r--r-- | kernel/bpf/syscall.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index ebeb0695305a..53a0b62464e9 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -5505,6 +5505,7 @@ int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size) run_ctx.saved_run_ctx = NULL; if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) { /* recursion detected */ + __bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx); bpf_prog_put(prog); return -EBUSY; } |