4.9-stable review patch. If anyone has any objections, please let me know.
------------------
[ Upstream commit 9bd2bbc01d17ddd567cc0f81f77fe1163e497462 ]
gcc 7.1 reports the following warning:
block/elevator.c: In function ‘elv_register’:
block/elevator.c:898:5: warning: ‘snprintf’ output may be truncated before
the last format character [-Wformat-truncation=]
"%s_io_cq", e->elevator_name);
^~~~~~~~~~
block/elevator.c:897:3: note: ‘snprintf’ output between 7 and 22 bytes into
a destination of size 21
snprintf(e->icq_cache_name, sizeof(e->icq_cache_name),
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"%s_io_cq", e->elevator_name);
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The bug is that the name of the icq_cache is 6 characters longer than
the elevator name, but only ELV_NAME_MAX + 5 characters were reserved
for it --- so in the case of a maximum-length elevator name, the 'q'
character in "_io_cq" would be truncated by snprintf(). Fix it by
reserving ELV_NAME_MAX + 6 characters instead.
Signed-off-by: Eric Biggers <[email protected]>
Reviewed-by: Bart Van Assche <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
---
include/linux/elevator.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/elevator.h b/include/linux/elevator.h
index e7f358d2e5fc..eaa58c0f894b 100644
--- a/include/linux/elevator.h
+++ b/include/linux/elevator.h
@@ -102,7 +102,7 @@ struct elevator_type
struct module *elevator_owner;
/* managed by elevator core */
- char icq_cache_name[ELV_NAME_MAX + 5]; /* elvname + "_io_cq" */
+ char icq_cache_name[ELV_NAME_MAX + 6]; /* elvname + "_io_cq" */
struct list_head list;
};
--
2.17.1
