On (24/09/24 10:42), Sergey Senozhatsky wrote:
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
As a minor side note, I'd still prefer to drop that backtrace from the commit message - we know that reset_store() is called from sysfs write, there is nothing new (nor important) in that call trace.