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authorAndrey Skvortsov <andrej.skvortzov@gmail.com>2024-09-23 19:48:43 +0300
committerAndrew Morton <akpm@linux-foundation.org>2024-09-27 00:01:44 +0300
commit486fd58af7ac1098b68370b1d4d9f94a2a1c7124 (patch)
tree19e6a9dcca1bca5f273732ccf89f81bd00b0fb86
parenta530bbc53826c607f64e8ee466c3351efaf6aea5 (diff)
downloadlinux-486fd58af7ac1098b68370b1d4d9f94a2a1c7124.tar.xz
zram: don't free statically defined names
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@gmail.com Fixes: 684826f8271a ("zram: free secondary algorithms names") Signed-off-by: Andrey Skvortsov <andrej.skvortzov@gmail.com> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Reported-by: Venkat Rao Bagalkote <venkat88@linux.vnet.ibm.com> Closes: https://lore.kernel.org/lkml/57130e48-dbb6-4047-a8c7-ebf5aaea93f4@linux.vnet.ibm.com/ Tested-by: Venkat Rao Bagalkote <venkat88@linux.vnet.ibm.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Jens Axboe <axboe@kernel.dk> Cc: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Venkat Rao Bagalkote <venkat88@linux.vnet.ibm.com> Cc: Chris Li <chrisl@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r--drivers/block/zram/zram_drv.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index c3d245617083..ad9c9bc3ccfc 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -2115,8 +2115,10 @@ 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;
}