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| author | Mikulas Patocka <mpatocka@redhat.com> | 2017-11-07 10:35:57 -0500 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2017-11-10 15:44:58 -0500 |
| commit | 0440d5c0ca9744b92a07aeb6df0a9a75db6f4280 (patch) | |
| tree | aedd27d5797516e04afecd33f0d224201042ea2b /drivers/md/dm-crypt.c | |
| parent | 49de5769702cdf997e87359ba4e9ae289c1044e0 (diff) | |
| download | lwn-0440d5c0ca9744b92a07aeb6df0a9a75db6f4280.tar.gz lwn-0440d5c0ca9744b92a07aeb6df0a9a75db6f4280.zip | |
dm crypt: allow unaligned bv_offset
When slub_debug is enabled kmalloc returns unaligned memory. XFS uses
this unaligned memory for its buffers (if an unaligned buffer crosses a
page, XFS frees it and allocates a full page instead - see the function
xfs_buf_allocate_memory).
dm-crypt checks if bv_offset is aligned on page size and these checks
fail with slub_debug and XFS.
Fix this bug by removing the bv_offset checks. Switch to checking if
bv_len is aligned instead of bv_offset (this check should be sufficient
to prevent overruns if a bio with too small bv_len is received).
Fixes: 8f0009a22517 ("dm crypt: optionally support larger encryption sector size")
Cc: stable@vger.kernel.org # v4.12+
Reported-by: Bruno Prémont <bonbons@sysophe.eu>
Tested-by: Bruno Prémont <bonbons@sysophe.eu>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-crypt.c')
| -rw-r--r-- | drivers/md/dm-crypt.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index 96ab46512e1f..9fc12f556534 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -1075,7 +1075,7 @@ static int crypt_convert_block_aead(struct crypt_config *cc, BUG_ON(cc->integrity_iv_size && cc->integrity_iv_size != cc->iv_size); /* Reject unexpected unaligned bio. */ - if (unlikely(bv_in.bv_offset & (cc->sector_size - 1))) + if (unlikely(bv_in.bv_len & (cc->sector_size - 1))) return -EIO; dmreq = dmreq_of_req(cc, req); @@ -1168,7 +1168,7 @@ static int crypt_convert_block_skcipher(struct crypt_config *cc, int r = 0; /* Reject unexpected unaligned bio. */ - if (unlikely(bv_in.bv_offset & (cc->sector_size - 1))) + if (unlikely(bv_in.bv_len & (cc->sector_size - 1))) return -EIO; dmreq = dmreq_of_req(cc, req); |