+ mm-vmalloc-fix-return-value-of-vb_alloc-if-size-is-0.patch added to mm-hotfixes-unstable branch

+ mm-vmalloc-fix-return-value-of-vb_alloc-if-size-is-0.patch added to mm-hotfixes-unstable branch

[Andrew Morton]

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

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: "Hailong.Liu" <hailong.liu@oppo.com>
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@oppo.com
Reviewed-by: Barry Song <baohua@kernel.org>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Hailong.Liu <hailong.liu@oppo.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 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@oppo.com are

mm-vmalloc-fix-return-value-of-vb_alloc-if-size-is-0.patch