The change is similar to that is used in comp_algorithm_set.
default_compressor is used for ZRAM_PRIMARY_COMP only, but if
CONFIG_ZRAM_MULTI_COMP isn't set, then ZRAM_PRIMARY_COMP and
ZRAM_SECONDARY_COMP are the same.
This is detected by KASAN.
==================================================================
Call trace:
kfree+0x60/0x3a0
zram_destroy_comps+0x98/0x198 [zram]
zram_reset_device+0x22c/0x4a8 [zram]
reset_store+0x1bc/0x2d8 [zram]
dev_attr_store+0x44/0x80
sysfs_kf_write+0xfc/0x188
kernfs_fop_write_iter+0x28c/0x428
vfs_write+0x4dc/0x9b8
ksys_write+0x100/0x1f8
__arm64_sys_write+0x74/0xb8
invoke_syscall+0xd8/0x260
el0_svc_common.constprop.0+0xb4/0x240
do_el0_svc+0x48/0x68
el0_svc+0x40/0xc8
el0t_64_sync_handler+0x120/0x130
el0t_64_sync+0x190/0x198
==================================================================
Signed-off-by: Andrey Skvortsov <andrej.skvortzov@xxxxxxxxx>
Fixes: 684826f8271a ("zram: free secondary algorithms names")
Cc: <stable@xxxxxxxxxxxxxxx>
---
Changes in v2:
- removed comment from source code about freeing statically defined compression
- removed part of KASAN report from commit description
- added information about CONFIG_ZRAM_MULTI_COMP into commit description
drivers/block/zram/zram_drv.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index c3d245617083d..4a9cdb7fe8878 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -2116,7 +2116,8 @@ static void zram_destroy_comps(struct zram *zram)
}
for (prio = ZRAM_SECONDARY_COMP; prio < ZRAM_MAX_COMPS; prio++) {
- kfree(zram->comp_algs[prio]);
+ if (zram->comp_algs[prio] != default_compressor)
+ kfree(zram->comp_algs[prio]);
zram->comp_algs[prio] = NULL;
}
--
2.45.2
