From: Wei Yongjun <weiyongjun1@xxxxxxxxxx>
commit 71e843295c680898959b22dc877ae3839cc22470 upstream.
kmemleak report memory leak as follows:
unreferenced object 0x607ee4e5f948 (size 8):
comm "syz-executor.1", pid 2098, jiffies 4295031601 (age 288.468s)
hex dump (first 8 bytes):
00 00 00 00 00 00 00 00 ........
backtrace:
relay_open kernel/relay.c:583 [inline]
relay_open+0xb6/0x970 kernel/relay.c:563
do_blk_trace_setup+0x4a8/0xb20 kernel/trace/blktrace.c:557
__blk_trace_setup+0xb6/0x150 kernel/trace/blktrace.c:597
blk_trace_ioctl+0x146/0x280 kernel/trace/blktrace.c:738
blkdev_ioctl+0xb2/0x6a0 block/ioctl.c:613
block_ioctl+0xe5/0x120 fs/block_dev.c:1871
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x170/0x1ce fs/ioctl.c:739
do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
'chan->buf' is malloced in relay_open() by alloc_percpu() but not free
while destroy the relay channel. Fix it by adding free_percpu() before
return from relay_destroy_channel().
Fixes: 017c59c042d0 ("relay: Use per CPU constructs for the relay channel buffer pointers")
Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
Signed-off-by: Wei Yongjun <weiyongjun1@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Reviewed-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Michel Lespinasse <walken@xxxxxxxxxx>
Cc: Daniel Axtens <dja@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Akash Goel <akash.goel@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20200817122826.48518-1-weiyongjun1@xxxxxxxxxx
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/relay.c | 1 +
1 file changed, 1 insertion(+)
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -196,6 +196,7 @@ free_buf:
static void relay_destroy_channel(struct kref *kref)
{
struct rchan *chan = container_of(kref, struct rchan, kref);
+ free_percpu(chan->buf);
kfree(chan);
}
