[PATCH 6.1 158/195] afs: Increase buffer size in afs_update_volume_status()

Greg Kroah-Hartman
2024-02-27T14:19:37Z

From: Daniil Dulov <d.dulov@aladdin.ru>

[ Upstream commit 6ea38e2aeb72349cad50e38899b0ba6fbcb2af3d ]

The max length of volume->vid value is 20 characters.
So increase idbuf[] size up to 24 to avoid overflow.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

[DH: Actually, it's 20 + NUL, so increase it to 24 and use snprintf()]

Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation")
Signed-off-by: Daniil Dulov <d.dulov@aladdin.ru>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20240211150442.3416-1-d.dulov@aladdin.ru/ # v1
Link: https://lore.kernel.org/r/20240212083347.10742-1-d.dulov@aladdin.ru/ # v2
Link: https://lore.kernel.org/r/20240219143906.138346-3-dhowells@redhat.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/afs/volume.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/afs/volume.c b/fs/afs/volume.c
index 1c9144e3e83ac..a146d70efa650 100644
--- a/fs/afs/volume.c
+++ b/fs/afs/volume.c
@@ -341,7 +341,7 @@ static int afs_update_volume_status(struct afs_volume *volume, struct key *key)
{
struct afs_server_list *new, *old, *discard;
struct afs_vldb_entry *vldb;
- char idbuf[16];
+ char idbuf[24];
int ret, idsz;

_enter("");
@@ -349,7 +349,7 @@ static int afs_update_volume_status(struct afs_volume *volume, struct key *key)
/* We look up an ID by passing it as a decimal string in the
* operation's name parameter.
*/
- idsz = sprintf(idbuf, "%llu", volume->vid);
+ idsz = snprintf(idbuf, sizeof(idbuf), "%llu", volume->vid);

vldb = afs_vl_lookup_vldb(volume->cell, key, idbuf, idsz);
if (IS_ERR(vldb)) {
--
2.43.0