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authorYishai Hadas <yishaih@nvidia.com>2023-01-05 13:23:39 +0200
committerJason Gunthorpe <jgg@nvidia.com>2023-01-05 16:01:05 -0400
commite95d50d74b93a767a026f588e8de0b9718a0105e (patch)
treee82ab6b8a095c764d6b37edb14059a1bec857cc4
parent8de8482fe5732fbef4f5af82bc0c0362c804cd1f (diff)
downloadlinux-e95d50d74b93a767a026f588e8de0b9718a0105e.tar.bz2
lib/scatterlist: Fix to merge contiguous pages into the last SG properly
When sg_alloc_append_table_from_pages() calls to pages_are_mergeable() in its 'sgt_append->prv' flow to check whether it can merge contiguous pages into the last SG, it passes the page arguments in the wrong order. The first parameter should be the next candidate page to be merged to the last page and not the opposite. The current code leads to a corrupted SG which resulted in OOPs and unexpected errors when non-contiguous pages are merged wrongly. Fix to pass the page parameters in the right order. Fixes: 1567b49d1a40 ("lib/scatterlist: add check when merging zone device pages") Link: https://lore.kernel.org/r/20230105112339.107969-1-yishaih@nvidia.com Signed-off-by: Yishai Hadas <yishaih@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
-rw-r--r--lib/scatterlist.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index a0ad2a7959b5..f72aa50c6654 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -476,7 +476,7 @@ int sg_alloc_append_table_from_pages(struct sg_append_table *sgt_append,
/* Merge contiguous pages into the last SG */
prv_len = sgt_append->prv->length;
last_pg = sg_page(sgt_append->prv);
- while (n_pages && pages_are_mergeable(last_pg, pages[0])) {
+ while (n_pages && pages_are_mergeable(pages[0], last_pg)) {
if (sgt_append->prv->length + PAGE_SIZE > max_segment)
break;
sgt_append->prv->length += PAGE_SIZE;