linux.git/crypto/af_alg.c, branch v6.5

crypto: fix uninit-value in af_alg_free_resources

2023-08-18T10:30:09+00:00

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 
Signed-off-by: Herbert Xu

crypto: af_alg - Fix merging of written data into spliced pages

2023-07-05T08:14:24+00:00

af_alg_sendmsg() takes data-to-be-copied that's provided by write(),
send(), sendmsg() and similar into pages that it allocates and will merge
new data into the last page in the list, based on the value of ctx->merge.

Now that af_alg_sendmsg() accepts MSG_SPLICE_PAGES, it adds spliced pages
directly into the list and then incorrectly appends data to them if there's
space left because ctx->merge says that it can.  This was cleared by
af_alg_sendpage(), but that got lost.

Fix this by skipping the merge if MSG_SPLICE_PAGES is specified and
clearing ctx->merge after MSG_SPLICE_PAGES has added stuff to the list.

Fixes: bf63e250c4b1 ("crypto: af_alg: Support MSG_SPLICE_PAGES")
Reported-by: Ondrej Mosnáček 
Link: https://lore.kernel.org/r/CAAUqJDvFuvms55Td1c=XKv6epfRnnP78438nZQ-JKyuCptGBiQ@mail.gmail.com/
Signed-off-by: David Howells 
cc: Herbert Xu 
cc: Paolo Abeni 
cc: "David S. Miller" 
cc: Eric Dumazet 
cc: Jakub Kicinski 
cc: linux-crypto@vger.kernel.org
cc: netdev@vger.kernel.org
Signed-off-by: Herbert Xu

sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES)

2023-06-24T22:50:13+00:00

Remove ->sendpage() and ->sendpage_locked().  sendmsg() with
MSG_SPLICE_PAGES should be used instead.  This allows multiple pages and
multipage folios to be passed through.

Signed-off-by: David Howells 
Acked-by: Marc Kleine-Budde  # for net/can
cc: Jens Axboe 
cc: Matthew Wilcox 
cc: linux-afs@lists.infradead.org
cc: mptcp@lists.linux.dev
cc: rds-devel@oss.oracle.com
cc: tipc-discussion@lists.sourceforge.net
cc: virtualization@lists.linux-foundation.org
Link: https://lore.kernel.org/r/20230623225513.2732256-16-dhowells@redhat.com
Signed-off-by: Jakub Kicinski

crypto: Fix af_alg_sendmsg(MSG_SPLICE_PAGES) sglist limit

2023-06-18T13:26:21+00:00

When af_alg_sendmsg() calls extract_iter_to_sg(), it passes MAX_SGL_ENTS as
the maximum number of elements that may be written to, but some of the
elements may already have been used (as recorded in sgl->cur), so
extract_iter_to_sg() may end up overrunning the scatterlist.

Fix this to limit the number of elements to "MAX_SGL_ENTS - sgl->cur".

Note: It probably makes sense in future to alter the behaviour of
extract_iter_to_sg() to stop if "sgtable->nents >= sg_max" instead, but
this is a smaller fix for now.

The bug causes errors looking something like:

BUG: KASAN: slab-out-of-bounds in sg_assign_page include/linux/scatterlist.h:109 [inline]
BUG: KASAN: slab-out-of-bounds in sg_set_page include/linux/scatterlist.h:139 [inline]
BUG: KASAN: slab-out-of-bounds in extract_bvec_to_sg lib/scatterlist.c:1183 [inline]
BUG: KASAN: slab-out-of-bounds in extract_iter_to_sg lib/scatterlist.c:1352 [inline]
BUG: KASAN: slab-out-of-bounds in extract_iter_to_sg+0x17a6/0x1960 lib/scatterlist.c:1339

Fixes: bf63e250c4b1 ("crypto: af_alg: Support MSG_SPLICE_PAGES")
Reported-by: syzbot+6efc50cc1f8d718d6cb7@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/000000000000b2585a05fdeb8379@google.com/
Signed-off-by: David Howells 
Tested-by: syzbot+6efc50cc1f8d718d6cb7@syzkaller.appspotmail.com
cc: Herbert Xu 
cc: "David S. Miller" 
cc: Eric Dumazet 
cc: Jakub Kicinski 
cc: Paolo Abeni 
cc: Jens Axboe 
cc: Matthew Wilcox 
cc: linux-crypto@vger.kernel.org
cc: netdev@vger.kernel.org
Acked-by: Herbert Xu 
Signed-off-by: David S. Miller

crypto: af_alg/hash: Support MSG_SPLICE_PAGES

2023-06-08T11:42:34+00:00

Make AF_ALG sendmsg() support MSG_SPLICE_PAGES in the hashing code.  This
causes pages to be spliced from the source iterator if possible.

This allows ->sendpage() to be replaced by something that can handle
multiple multipage folios in a single transaction.

Signed-off-by: David Howells 
cc: Herbert Xu 
cc: "David S. Miller" 
cc: Eric Dumazet 
cc: Jakub Kicinski 
cc: Paolo Abeni 
cc: Jens Axboe 
cc: Matthew Wilcox 
cc: linux-crypto@vger.kernel.org
cc: netdev@vger.kernel.org
Acked-by: Herbert Xu 
Signed-off-by: Paolo Abeni

crypto: af_alg: Convert af_alg_sendpage() to use MSG_SPLICE_PAGES

2023-06-08T11:42:34+00:00

Convert af_alg_sendpage() to use sendmsg() with MSG_SPLICE_PAGES rather
than directly splicing in the pages itself.

This allows ->sendpage() to be replaced by something that can handle
multiple multipage folios in a single transaction.

Signed-off-by: David Howells 
cc: Herbert Xu 
cc: "David S. Miller" 
cc: Eric Dumazet 
cc: Jakub Kicinski 
cc: Paolo Abeni 
cc: Jens Axboe 
cc: Matthew Wilcox 
cc: linux-crypto@vger.kernel.org
cc: netdev@vger.kernel.org
Acked-by: Herbert Xu 
Signed-off-by: Paolo Abeni

crypto: af_alg: Support MSG_SPLICE_PAGES

2023-06-08T11:42:34+00:00

Make AF_ALG sendmsg() support MSG_SPLICE_PAGES.  This causes pages to be
spliced from the source iterator.

This allows ->sendpage() to be replaced by something that can handle
multiple multipage folios in a single transaction.

Signed-off-by: David Howells 
cc: Herbert Xu 
cc: "David S. Miller" 
cc: Eric Dumazet 
cc: Jakub Kicinski 
cc: Paolo Abeni 
cc: Jens Axboe 
cc: Matthew Wilcox 
cc: linux-crypto@vger.kernel.org
cc: netdev@vger.kernel.org
Acked-by: Herbert Xu 
Signed-off-by: Paolo Abeni

crypto: af_alg: Indent the loop in af_alg_sendmsg()

2023-06-08T11:42:34+00:00

Put the loop in af_alg_sendmsg() into an if-statement to indent it to make
the next patch easier to review as that will add another branch to handle
MSG_SPLICE_PAGES to the if-statement.

Signed-off-by: David Howells 
cc: Herbert Xu 
cc: "David S. Miller" 
cc: Eric Dumazet 
cc: Jakub Kicinski 
cc: Paolo Abeni 
cc: Jens Axboe 
cc: Matthew Wilcox 
cc: linux-crypto@vger.kernel.org
cc: netdev@vger.kernel.org
Acked-by: Herbert Xu 
Signed-off-by: Paolo Abeni

crypto: af_alg: Use extract_iter_to_sg() to create scatterlists

2023-06-08T11:42:34+00:00

Use extract_iter_to_sg() to decant the destination iterator into a
scatterlist in af_alg_get_rsgl().  af_alg_make_sg() can then be removed.

Signed-off-by: David Howells 
cc: Herbert Xu 
cc: "David S. Miller" 
cc: Eric Dumazet 
cc: Jakub Kicinski 
cc: Paolo Abeni 
cc: Jens Axboe 
cc: Matthew Wilcox 
cc: linux-crypto@vger.kernel.org
cc: netdev@vger.kernel.org
Acked-by: Herbert Xu 
Signed-off-by: Paolo Abeni

crypto: af_alg: Pin pages rather than ref'ing if appropriate

2023-06-08T11:42:34+00:00

Convert AF_ALG to use iov_iter_extract_pages() instead of
iov_iter_get_pages().  This will pin pages or leave them unaltered rather
than getting a ref on them as appropriate to the iterator.

The pages need to be pinned for DIO-read rather than having refs taken on
them to prevent VM copy-on-write from malfunctioning during a concurrent
fork() (the result of the I/O would otherwise end up only visible to the
child process and not the parent).

Signed-off-by: David Howells 
cc: Herbert Xu 
cc: "David S. Miller" 
cc: Eric Dumazet 
cc: Jakub Kicinski 
cc: Paolo Abeni 
cc: Jens Axboe 
cc: Matthew Wilcox 
cc: linux-crypto@vger.kernel.org
cc: netdev@vger.kernel.org
Acked-by: Herbert Xu 
Signed-off-by: Paolo Abeni