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authorPavel Skripkin <paskripkin@gmail.com>2023-08-14 21:03:41 +0300
committerHerbert Xu <herbert@gondor.apana.org.au>2023-08-18 18:30:09 +0800
commit080aa61e370b9c5cafe71cacadbfe0e72db4d6df (patch)
treee36d58dc6d430b6fc968c771b357a545a2181d93 /crypto/af_alg.c
parent83874b8e97f895e62d9ab03223318176d5e78203 (diff)
crypto: fix uninit-value in af_alg_free_resources
Syzbot was able to trigger use of uninitialized memory in af_alg_free_resources. Bug is caused by missing initialization of rsgl->sgl.need_unpin before adding to rsgl_list. Then in case of extract_iter_to_sg() failure, rsgl is left with uninitialized need_unpin which is read during clean up BUG: KMSAN: uninit-value in af_alg_free_sg crypto/af_alg.c:545 [inline] BUG: KMSAN: uninit-value in af_alg_free_areq_sgls crypto/af_alg.c:778 [inline] BUG: KMSAN: uninit-value in af_alg_free_resources+0x3d1/0xf60 crypto/af_alg.c:1117 af_alg_free_sg crypto/af_alg.c:545 [inline] af_alg_free_areq_sgls crypto/af_alg.c:778 [inline] af_alg_free_resources+0x3d1/0xf60 crypto/af_alg.c:1117 _skcipher_recvmsg crypto/algif_skcipher.c:144 [inline] ... Uninit was created at: slab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767 slab_alloc_node mm/slub.c:3470 [inline] __kmem_cache_alloc_node+0x536/0x8d0 mm/slub.c:3509 __do_kmalloc_node mm/slab_common.c:984 [inline] __kmalloc+0x121/0x3c0 mm/slab_common.c:998 kmalloc include/linux/slab.h:586 [inline] sock_kmalloc+0x128/0x1c0 net/core/sock.c:2683 af_alg_alloc_areq+0x41/0x2a0 crypto/af_alg.c:1188 _skcipher_recvmsg crypto/algif_skcipher.c:71 [inline] Fixes: c1abe6f570af ("crypto: af_alg: Use extract_iter_to_sg() to create scatterlists") Reported-and-tested-by: syzbot+cba21d50095623218389@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=cba21d50095623218389 Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto/af_alg.c')
-rw-r--r--crypto/af_alg.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index 06b15b9f661c..10efb56d8b48 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -1241,6 +1241,8 @@ int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
return -ENOMEM;
}
+ rsgl->sgl.need_unpin =
+ iov_iter_extract_will_pin(&msg->msg_iter);
rsgl->sgl.sgt.sgl = rsgl->sgl.sgl;
rsgl->sgl.sgt.nents = 0;
rsgl->sgl.sgt.orig_nents = 0;
@@ -1255,8 +1257,6 @@ int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
}
sg_mark_end(rsgl->sgl.sgt.sgl + rsgl->sgl.sgt.nents - 1);
- rsgl->sgl.need_unpin =
- iov_iter_extract_will_pin(&msg->msg_iter);
/* chain the new scatterlist with previous one */
if (areq->last_rsgl)