The patch titled
Subject: mm/vmalloc: fix return value of vb_alloc if size is 0
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
mm-vmalloc-fix-return-value-of-vb_alloc-if-size-is-0.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-vmalloc-fix-return-value-of-vb_alloc-if-size-is-0.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Hailong.Liu" <hailong.liu@xxxxxxxx>
Subject: mm/vmalloc: fix return value of vb_alloc if size is 0
Date: Fri, 26 Apr 2024 10:41:49 +0800
vm_map_ram() uses IS_ERR() to validate the return value of vb_alloc(). If
vm_map_ram(page, 0, 0) is executed, vb_alloc(0, GFP_KERNEL) would return
NULL. In such a case, IS_ERR() cannot handle the return value and lead to
kernel panic by vmap_pages_range_noflush() at last. To resolve this
issue, return ERR_PTR(-EINVAL) if the size is 0.
Link: https://lkml.kernel.org/r/20240426024149.21176-1-hailong.liu@xxxxxxxx
Reviewed-by: Barry Song <baohua@xxxxxxxxxx>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
Signed-off-by: Hailong.Liu <hailong.liu@xxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Cc: Lorenzo Stoakes <lstoakes@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmalloc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/vmalloc.c~mm-vmalloc-fix-return-value-of-vb_alloc-if-size-is-0
+++ a/mm/vmalloc.c
@@ -2710,7 +2710,7 @@ static void *vb_alloc(unsigned long size
* get_order(0) returns funny result. Just warn and terminate
* early.
*/
- return NULL;
+ return ERR_PTR(-EINVAL);
}
order = get_order(size);
_
Patches currently in -mm which might be from hailong.liu@xxxxxxxx are
mm-vmalloc-fix-return-value-of-vb_alloc-if-size-is-0.patch
