When user requests encryption (or decryption) of block which is not aligned to cipher block size through userspace crypto interface, an OOps like this can happen: [ 112.738285] BUG: unable to handle kernel paging request at e1c44840 [ 112.738407] IP: [<c121f473>] scatterwalk_done+0x53/0x70 ... [ 112.740515] Call Trace: [ 112.740588] [<c1221d30>] blkcipher_walk_done+0x160/0x1e0 [ 112.740663] [<c12220c8>] blkcipher_walk_next+0x318/0x3c0 [ 112.740737] [<c12221e0>] blkcipher_walk_first+0x70/0x160 [ 112.740811] [<c1222327>] blkcipher_walk_virt+0x17/0x20 [ 112.740886] [<e0ce4249>] cbc_encrypt+0x29/0x100 [aesni_intel] [ 112.740968] [<c1029f73>] ? get_user_pages_fast+0x123/0x150 [ 112.741046] [<c106e7db>] ? trace_hardirqs_on+0xb/0x10 [ 112.741119] [<e081e1c9>] __ablk_encrypt+0x39/0x40 [ablk_helper] [ 112.741198] [<e081e1ea>] ablk_encrypt+0x1a/0x70 [ablk_helper] [ 112.741275] [<e0f715ac>] skcipher_recvmsg+0x20c/0x400 [algif_skcipher] [ 112.741359] [<c1056a1d>] ? sched_clock_cpu+0x11d/0x1a0 [ 112.741435] [<c10a5eb9>] ? find_get_page+0x79/0xc0 [ 112.741509] [<c135e034>] sock_aio_read+0x104/0x140 [ 112.741580] [<c10be638>] ? __do_fault+0x248/0x420 [ 112.741650] [<c10d3d27>] do_sync_read+0x97/0xd0 [ 112.741719] [<c10d45ed>] vfs_read+0x11d/0x140 [ 112.741789] [<c135f683>] ? sys_socketcall+0x2a3/0x320 [ 112.741861] [<c10d4762>] sys_read+0x42/0x90 [ 112.742578] [<c141c27a>] sysenter_do_call+0x12/0x32 Patch fixes it by simply rejecting buffer which is not multiple of cipher block. (Bug is present in all stable kernels as well.) Signed-off-by: Milan Broz <gmazyland@xxxxxxxxx> --- crypto/algif_skcipher.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c index 6a6dfc0..5f7713b 100644 --- a/crypto/algif_skcipher.c +++ b/crypto/algif_skcipher.c @@ -463,7 +463,7 @@ static int skcipher_recvmsg(struct kiocb *unused, struct socket *sock, used -= used % bs; err = -EINVAL; - if (!used) + if (!used || used % bs) goto free; ablkcipher_request_set_crypt(&ctx->req, sg, -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
