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target: fix crash with iscsi target and dvd

PATCH In review Ming Lei 4 participants 5 messages Apr 16, 2018 – Apr 19, 2018

Subsystems (2)
Block layer SCSI target
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Ming Lei

author
#0 lore raw

PATCH 1/1 target: fix crash with iscsi target and dvd

When the current page can't be added to bio, one new bio should be created for adding this page again, instead of ignoring this page.

This patch fixes kernel crash with iscsi target and dvd, as reported by Wakko.

Cc Wakko Warner <[email protected]>
Cc Bart Van Assche <[email protected]>
Cc [email protected]
Cc [email protected]
Cc "Nicholas A. Bellinger" <[email protected]>
Cc Christoph Hellwig <[email protected]>
Fixes 84c8590646d5b35804 ("target: avoid accessing .bi_vcnt directly")
Signed-off-by Ming Lei <[email protected]>
---
 drivers/target/target_core_pscsi.c | 2 ++
 1 file changed, 2 insertions(+)
drivers/target/target_core_pscsi.c +2 -0
index 0d99b242e82e..6cb933ecc084 100644
@@ -890,6 +890,7 @@ pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 			bytes = min(bytes, data_len);
 
 			if (!bio) {
+new_bio:
 				nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages);
 				nr_pages -= nr_vecs;
 				/*

@@ -931,6 +932,7 @@ pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 				 * be allocated with pscsi_get_bio() above.
 				 */
 				bio = NULL;
+				goto new_bio;
 			}
 
 			data_len -= bytes;
Signature · 1 line
2.9.5
Reviewed-by on v1 1/1
#1 lore raw

Looks good,

Reviewed-by Christoph Hellwig <[email protected]>

Btw, seems like someone needs to volunteer for putting together a pull request with target fixes for Linus - I haven't heard from Nic for a while, and we've got quite a few fixes out on the list.

#2 lore raw

Christoph,

Quoted 3 lines

Btw, seems like someone needs to volunteer for putting together a pull request with target fixes for Linus - I haven't heard from Nic for a while, and we've got quite a few fixes out on the list.

Still happy to take things through SCSI if Nic doesn't materialize.

Signature · 1 line
Martin K. Petersen	Oracle Linux Engineering
#3 lore raw

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#4 lore raw
In reply to Ming Lei

Ming,

Quoted 5 lines

When the current page can't be added to bio, one new bio should be created for adding this page again, instead of ignoring this page.

This patch fixes kernel crash with iscsi target and dvd, as reported by Wakko.

I queued this up in 4.17/scsi-fixes.

Signature · 1 line
Martin K. Petersen	Oracle Linux Engineering