Commit 93278814 authored by Sasha Levin's avatar Sasha Levin Committed by Linus Torvalds

mm: fix division by 0 in percpu_pagelist_fraction()

percpu_pagelist_fraction_sysctl_handler() has only considered -EINVAL as
a possible error from proc_dointvec_minmax().

If any other error is returned, it would proceed to divide by zero since
percpu_pagelist_fraction wasn't getting initialized at any point.  For
example, writing 0 bytes into the proc file would trigger the issue.
Signed-off-by: default avatarSasha Levin <levinsasha928@gmail.com>
Reviewed-by: default avatarMinchan Kim <minchan@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 16fbdce6
......@@ -105,7 +105,7 @@ unsigned long totalreserve_pages __read_mostly;
*/
unsigned long dirty_balance_reserve __read_mostly;
int percpu_pagelist_fraction;
int percpu_pagelist_fraction = 8;
gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
#ifdef CONFIG_PM_SLEEP
......@@ -5203,7 +5203,7 @@ int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
int ret;
ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
if (!write || (ret == -EINVAL))
if (!write || (ret < 0))
return ret;
for_each_populated_zone(zone) {
for_each_possible_cpu(cpu) {
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment