From: Rustam Kovhaev rkovhaev@gmail.com
mainline-inclusion from mainline-v5.15-rc4 commit c30a0cbd07ecc0eec7b3cd568f7b1c7bb7913f93 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I4KIAO CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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For kmalloc() allocations SLOB prepends the blocks with a 4-byte header, and it puts the size of the allocated blocks in that header. Blocks allocated with kmem_cache_alloc() allocations do not have that header.
SLOB explodes when you allocate memory with kmem_cache_alloc() and then try to free it with kfree() instead of kmem_cache_free(). SLOB will assume that there is a header when there is none, read some garbage to size variable and corrupt the adjacent objects, which eventually leads to hang or panic.
Let's make XFS work with SLOB by using proper free function.
Fixes: 9749fee83f38 ("xfs: enable the xfs_defer mechanism to process extents to free") Signed-off-by: Rustam Kovhaev rkovhaev@gmail.com Reviewed-by: Darrick J. Wong djwong@kernel.org Signed-off-by: Darrick J. Wong djwong@kernel.org Signed-off-by: Guo Xuenan guoxuenan@huawei.com Reviewed-by: Lihong Kou koulihong@huawei.com Reviewed-by: Zhang Yi yi.zhang@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- fs/xfs/xfs_extfree_item.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/fs/xfs/xfs_extfree_item.c b/fs/xfs/xfs_extfree_item.c index 5c0395256bd1..11474770d630 100644 --- a/fs/xfs/xfs_extfree_item.c +++ b/fs/xfs/xfs_extfree_item.c @@ -482,7 +482,7 @@ xfs_extent_free_finish_item( free->xefi_startblock, free->xefi_blockcount, &free->xefi_oinfo, free->xefi_skip_discard); - kmem_free(free); + kmem_cache_free(xfs_bmap_free_item_zone, free); return error; }
@@ -502,7 +502,7 @@ xfs_extent_free_cancel_item( struct xfs_extent_free_item *free;
free = container_of(item, struct xfs_extent_free_item, xefi_list); - kmem_free(free); + kmem_cache_free(xfs_bmap_free_item_zone, free); }
const struct xfs_defer_op_type xfs_extent_free_defer_type = { @@ -564,7 +564,7 @@ xfs_agfl_free_finish_item( extp->ext_len = free->xefi_blockcount; efdp->efd_next_extent++;
- kmem_free(free); + kmem_cache_free(xfs_bmap_free_item_zone, free); return error; }