This is a note to let you know that I've just added the patch titled
pstore: ram_core: fix possible overflow in persistent_ram_init_ecc()
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pstore-ram_core-fix-possible-overflow-in-persistent_.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 0a4b12773259904045fdab3a5766ded079fd6c64
Author: Sergey Shtylyov <s.shtylyov@xxxxxx>
Date: Sun Nov 5 23:29:36 2023 +0300
pstore: ram_core: fix possible overflow in persistent_ram_init_ecc()
[ Upstream commit 86222a8fc16ec517de8da2604d904c9df3a08e5d ]
In persistent_ram_init_ecc(), on 64-bit arches DIV_ROUND_UP() will return
64-bit value since persistent_ram_zone::buffer_size has type size_t which
is derived from the 64-bit *unsigned long*, while the ecc_blocks variable
this value gets assigned to has (always 32-bit) *int* type. Even if that
value fits into *int* type, an overflow is still possible when calculating
the size_t typed ecc_total variable further below since there's no cast to
any 64-bit type before multiplication. Declaring the ecc_blocks variable
as *size_t* should fix this mess...
Found by Linux Verification Center (linuxtesting.org) with the SVACE static
analysis tool.
Fixes: 9cc05ad97c57 ("staging: android: persistent_ram: refactor ecc support")
Signed-off-by: Sergey Shtylyov <s.shtylyov@xxxxxx>
Link: https://lore.kernel.org/r/20231105202936.25694-1-s.shtylyov@xxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
index 650e437b55e6..f1848cdd6d34 100644
--- a/fs/pstore/ram_core.c
+++ b/fs/pstore/ram_core.c
@@ -190,7 +190,7 @@ static int persistent_ram_init_ecc(struct persistent_ram_zone *prz,
{
int numerr;
struct persistent_ram_buffer *buffer = prz->buffer;
- int ecc_blocks;
+ size_t ecc_blocks;
size_t ecc_total;
if (!ecc_info || !ecc_info->ecc_size)
