This is a note to let you know that I've just added the patch titled
zram: don't free statically defined names
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:
zram-don-t-free-statically-defined-names.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 3cba76e7dc5cedd04870351833938bf1e2692c30
Author: Andrey Skvortsov <andrej.skvortzov@xxxxxxxxx>
Date: Wed Oct 9 13:51:40 2024 +0900
zram: don't free statically defined names
[ Upstream commit 486fd58af7ac1098b68370b1d4d9f94a2a1c7124 ]
When CONFIG_ZRAM_MULTI_COMP isn't set ZRAM_SECONDARY_COMP can hold
default_compressor, because it's the same offset as ZRAM_PRIMARY_COMP, so
we need to make sure that we don't attempt to kfree() the statically
defined compressor name.
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
==================================================================
Link: https://lkml.kernel.org/r/20240923164843.1117010-1-andrej.skvortzov@xxxxxxxxx
Fixes: 684826f8271a ("zram: free secondary algorithms names")
Signed-off-by: Andrey Skvortsov <andrej.skvortzov@xxxxxxxxx>
Reviewed-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Reported-by: Venkat Rao Bagalkote <venkat88@xxxxxxxxxxxxxxxxxx>
Closes: https://lore.kernel.org/lkml/57130e48-dbb6-4047-a8c7-ebf5aaea93f4@xxxxxxxxxxxxxxxxxx/
Tested-by: Venkat Rao Bagalkote <venkat88@xxxxxxxxxxxxxxxxxx>
Cc: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Cc: Venkat Rao Bagalkote <venkat88@xxxxxxxxxxxxxxxxxx>
Cc: Chris Li <chrisl@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index db729035fd6bf..606f388c7a571 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1984,8 +1984,10 @@ static void zram_destroy_comps(struct zram *zram)
zram->num_active_comps--;
}
- for (prio = ZRAM_SECONDARY_COMP; prio < ZRAM_MAX_COMPS; prio++) {
- kfree(zram->comp_algs[prio]);
+ for (prio = ZRAM_PRIMARY_COMP; prio < ZRAM_MAX_COMPS; prio++) {
+ /* Do not free statically defined compression algorithms */
+ if (zram->comp_algs[prio] != default_compressor)
+ kfree(zram->comp_algs[prio]);
zram->comp_algs[prio] = NULL;
}
}
