Re: [PATCH v3] zram: don't free statically defined names

Sergey Senozhatsky
2024-09-24T01:42:46Z

On (24/09/23 19:48), Andrey Skvortsov wrote:
> 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
> ==================================================================
>
> Signed-off-by: Andrey Skvortsov <andrej.skvortzov@gmail.com>
> Fixes: 684826f8271a ("zram: free secondary algorithms names")
> Cc: <stable@vger.kernel.org>

Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>