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| author | Dominik Grzegorzek <dominik.grzegorzek@oracle.com> | 2025-05-18 19:45:31 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-06-04 14:40:20 +0200 |
| commit | cceb15864e1612ebfbc10ec4e4dcd19a10c0056c (patch) | |
| tree | b8ccbca462986a3e7b6e85325e59519fbf42829c | |
| parent | f0f3d09f53534ea385d55ced408f2b67059b16e4 (diff) | |
| download | linux-cceb15864e1612ebfbc10ec4e4dcd19a10c0056c.tar.gz linux-cceb15864e1612ebfbc10ec4e4dcd19a10c0056c.tar.bz2 linux-cceb15864e1612ebfbc10ec4e4dcd19a10c0056c.zip | |
padata: do not leak refcount in reorder_work
commit d6ebcde6d4ecf34f8495fb30516645db3aea8993 upstream.
A recent patch that addressed a UAF introduced a reference count leak:
the parallel_data refcount is incremented unconditionally, regardless
of the return value of queue_work(). If the work item is already queued,
the incremented refcount is never decremented.
Fix this by checking the return value of queue_work() and decrementing
the refcount when necessary.
Resolves:
Unreferenced object 0xffff9d9f421e3d80 (size 192):
comm "cryptomgr_probe", pid 157, jiffies 4294694003
hex dump (first 32 bytes):
80 8b cf 41 9f 9d ff ff b8 97 e0 89 ff ff ff ff ...A............
d0 97 e0 89 ff ff ff ff 19 00 00 00 1f 88 23 00 ..............#.
backtrace (crc 838fb36):
__kmalloc_cache_noprof+0x284/0x320
padata_alloc_pd+0x20/0x1e0
padata_alloc_shell+0x3b/0xa0
0xffffffffc040a54d
cryptomgr_probe+0x43/0xc0
kthread+0xf6/0x1f0
ret_from_fork+0x2f/0x50
ret_from_fork_asm+0x1a/0x30
Fixes: dd7d37ccf6b1 ("padata: avoid UAF for reorder_work")
Cc: <stable@vger.kernel.org>
Signed-off-by: Dominik Grzegorzek <dominik.grzegorzek@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | kernel/padata.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/padata.c b/kernel/padata.c index e2bef90e6fd0..b3f79f23060c 100644 --- a/kernel/padata.c +++ b/kernel/padata.c @@ -350,7 +350,8 @@ static void padata_reorder(struct parallel_data *pd) * To avoid UAF issue, add pd ref here, and put pd ref after reorder_work finish. */ padata_get_pd(pd); - queue_work(pinst->serial_wq, &pd->reorder_work); + if (!queue_work(pinst->serial_wq, &pd->reorder_work)) + padata_put_pd(pd); } } |