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| author | Stephan Mueller <smueller@chronox.de> | 2017-09-21 10:16:53 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-09-27 14:39:20 +0200 |
| commit | e684db9a7cea3f2cca6545b456e1bcaea836f994 (patch) | |
| tree | f43378be577e079d0eca55e50a88562d54cea21e /crypto | |
| parent | dcb3a4b8d7768cab59546aa2ce5dd214f7b526fe (diff) | |
| download | linux-stable-e684db9a7cea3f2cca6545b456e1bcaea836f994.tar.gz linux-stable-e684db9a7cea3f2cca6545b456e1bcaea836f994.tar.bz2 linux-stable-e684db9a7cea3f2cca6545b456e1bcaea836f994.zip | |
crypto: AF_ALG - remove SGL terminator indicator when chaining
Fixed differently upstream as commit 2d97591ef43d ("crypto: af_alg - consolidation of duplicate code")
The SGL is MAX_SGL_ENTS + 1 in size. The last SG entry is used for the
chaining and is properly updated with the sg_chain invocation. During
the filling-in of the initial SG entries, sg_mark_end is called for each
SG entry. This is appropriate as long as no additional SGL is chained
with the current SGL. However, when a new SGL is chained and the last
SG entry is updated with sg_chain, the last but one entry still contains
the end marker from the sg_mark_end. This end marker must be removed as
otherwise a walk of the chained SGLs will cause a NULL pointer
dereference at the last but one SG entry, because sg_next will return
NULL.
The patch only applies to all kernels up to and including 4.13. The
patch 2d97591ef43d0587be22ad1b0d758d6df4999a0b added to 4.14-rc1
introduced a complete new code base which addresses this bug in
a different way. Yet, that patch is too invasive for stable kernels
and was therefore not marked for stable.
Fixes: 8ff590903d5fc ("crypto: algif_skcipher - User-space interface for skcipher operations")
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'crypto')
| -rw-r--r-- | crypto/algif_skcipher.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c index 45af0fe00f33..aaf2f810d170 100644 --- a/crypto/algif_skcipher.c +++ b/crypto/algif_skcipher.c @@ -143,8 +143,10 @@ static int skcipher_alloc_sgl(struct sock *sk) sg_init_table(sgl->sg, MAX_SGL_ENTS + 1); sgl->cur = 0; - if (sg) + if (sg) { sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg); + sg_unmark_end(sg + (MAX_SGL_ENTS - 1)); + } list_add_tail(&sgl->list, &ctx->tsgl); } |