path: root/drivers/nvdimm/btt.c
diff options
authorDmitry Monakhov <dmonakhov@openvz.org>2017-06-29 11:31:13 -0700
committerJens Axboe <axboe@kernel.dk>2017-07-03 16:56:26 -0600
commitb1fb2c52b2d85f51f36f1661409f9aeef94265ff (patch)
tree26f345624f8f3a8adca8689916b2f9d69282051d /drivers/nvdimm/btt.c
parent128b6f9fdd9ace9e56cb3a263b4bc269658f9c40 (diff)
block: guard bvec iteration logic
Currently if some one try to advance bvec beyond it's size we simply dump WARN_ONCE and continue to iterate beyond bvec array boundaries. This simply means that we endup dereferencing/corrupting random memory region. Sane reaction would be to propagate error back to calling context But bvec_iter_advance's calling context is not always good for error handling. For safity reason let truncate iterator size to zero which will break external iteration loop which prevent us from unpredictable memory range corruption. And even it caller ignores an error, it will corrupt it's own bvecs, not others. This patch does: - Return error back to caller with hope that it will react on this - Truncate iterator size Code was added long time ago here 4550dd6c, luckily no one hit it in real life :) Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> [hch: switch to true/false returns instead of errno values] Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/nvdimm/btt.c')
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c
index b5caaee78bbf..d00c10f382f0 100644
--- a/drivers/nvdimm/btt.c
+++ b/drivers/nvdimm/btt.c
@@ -985,7 +985,8 @@ static int btt_rw_integrity(struct btt *btt, struct bio_integrity_payload *bip,
len -= cur_len;
meta_nsoff += cur_len;
- bvec_iter_advance(bip->bip_vec, &bip->bip_iter, cur_len);
+ if (!bvec_iter_advance(bip->bip_vec, &bip->bip_iter, cur_len))
+ return -EIO;
return ret;

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