From d6ebcde6d4ecf34f8495fb30516645db3aea8993 Mon Sep 17 00:00:00 2001 From: Dominik Grzegorzek Date: Sun, 18 May 2025 19:45:31 +0200 Subject: [PATCH 1/2] padata: do not leak refcount in reorder_work 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: Signed-off-by: Dominik Grzegorzek Signed-off-by: Herbert Xu --- kernel/padata.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/padata.c b/kernel/padata.c index b3d4eacc4f5d..7eee94166357 100644 --- a/kernel/padata.c +++ b/kernel/padata.c @@ -358,7 +358,8 @@ 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); } } From b2df03ed4052e97126267e8c13ad4204ea6ba9b6 Mon Sep 17 00:00:00 2001 From: Ivan Pravdin Date: Sun, 18 May 2025 18:41:02 -0400 Subject: [PATCH 2/2] crypto: algif_hash - fix double free in hash_accept If accept(2) is called on socket type algif_hash with MSG_MORE flag set and crypto_ahash_import fails, sk2 is freed. However, it is also freed in af_alg_release, leading to slab-use-after-free error. Fixes: fe869cdb89c9 ("crypto: algif_hash - User-space interface for hash operations") Cc: Signed-off-by: Ivan Pravdin Signed-off-by: Herbert Xu --- crypto/algif_hash.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/crypto/algif_hash.c b/crypto/algif_hash.c index 5498a87249d3..e3f1a4852737 100644 --- a/crypto/algif_hash.c +++ b/crypto/algif_hash.c @@ -265,10 +265,6 @@ static int hash_accept(struct socket *sock, struct socket *newsock, goto out_free_state; err = crypto_ahash_import(&ctx2->req, state); - if (err) { - sock_orphan(sk2); - sock_put(sk2); - } out_free_state: kfree_sensitive(state);