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| author |  Daniel Borkmann <daniel@iogearbox.net>
| 2023-05-26 12:13:56 +0200 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net>
| 2023-05-26 12:16:12 +0200 |
| commit | 4266f41feaeee2521749ce2cfb52eafd4e2947c5 (patch) | |
| tree | 93e49d931c5c4355463771d46cc181f643e1dd0b | |
| parent | libbpf: Ensure FD >= 3 during bpf_map__reuse_fd() (diff) | |
| download | linux-4266f41feaeee2521749ce2cfb52eafd4e2947c5.tar.gz linux-4266f41feaeee2521749ce2cfb52eafd4e2947c5.tar.bz2 linux-4266f41feaeee2521749ce2cfb52eafd4e2947c5.zip | |
bpf: Fix bad unlock balance on freeze_mutex
Commit c4c84f6fb2c4 ("bpf: drop unnecessary bpf_capable() check in
BPF_MAP_FREEZE command") moved the permissions check outside of the
freeze_mutex in the map_freeze() handler. The error paths still jumps
to the err_put which tries to unlock the freeze_mutex even though it
was not locked in the first place. Fix it.
Fixes: c4c84f6fb2c4 ("bpf: drop unnecessary bpf_capable() check in BPF_MAP_FREEZE command")
Reported-by: syzbot+8982e75c2878b9ffeac5@syzkaller.appspotmail.com
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| -rw-r--r-- | kernel/bpf/syscall.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index c9a201e4c457..92a57efc77de 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1932,8 +1932,8 @@ static int map_freeze(const union bpf_attr *attr) } if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { - err = -EPERM; - goto err_put; + fdput(f); + return -EPERM; } mutex_lock(&map->freeze_mutex); |