The patch titled
Subject: kernel/relay.c: revert "kernel/relay.c: fix potential memory leak"
has been added to the -mm tree. Its filename is
revert-kernel-relayc-fix-potential-memory-leak.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/revert-kernel-relayc-fix-potential-memory-leak.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/revert-kernel-relayc-fix-potential-memory-leak.patch
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------------------------------------------------------
From: Eric Biggers <ebiggers@xxxxxxxxxx>
Subject: kernel/relay.c: revert "kernel/relay.c: fix potential memory leak"
This reverts ba62bafe942b159a6 ("kernel/relay.c: fix potential memory leak").
This commit introduced a double free bug, because 'chan' is already
freed by the line:
kref_put(&chan->kref, relay_destroy_channel);
This bug was found by syzkaller, using the BLKTRACESETUP ioctl.
Link: http://lkml.kernel.org/r/20180127004759.101823-1-ebiggers3@xxxxxxxxx
Fixes: ba62bafe942b ("kernel/relay.c: fix potential memory leak")
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Zhouyi Zhou <yizhouzhou@xxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> [4.7+]
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/relay.c | 1 -
1 file changed, 1 deletion(-)
diff -puN kernel/relay.c~revert-kernel-relayc-fix-potential-memory-leak kernel/relay.c
--- a/kernel/relay.c~revert-kernel-relayc-fix-potential-memory-leak
+++ a/kernel/relay.c
@@ -611,7 +611,6 @@ free_bufs:
kref_put(&chan->kref, relay_destroy_channel);
mutex_unlock(&relay_channels_mutex);
- kfree(chan);
return NULL;
}
EXPORT_SYMBOL_GPL(relay_open);
_
Patches currently in -mm which might be from ebiggers@xxxxxxxxxx are
userfaultfd-convert-to-use-anon_inode_getfd.patch
revert-kernel-relayc-fix-potential-memory-leak.patch
pipe-sysctl-drop-min-parameter-from-pipe-max-size-converter.patch
pipe-sysctl-remove-pipe_proc_fn.patch
pipe-actually-allow-root-to-exceed-the-pipe-buffer-limits.patch
pipe-fix-off-by-one-error-when-checking-buffer-limits.patch
pipe-reject-f_setpipe_sz-with-size-over-uint_max.patch
pipe-simplify-round_pipe_size.patch
pipe-read-buffer-limits-atomically.patch