On Thu, Oct 21, 2021 at 2:01 PM Naresh Kamboju <naresh.kamboju@xxxxxxxxxx> wrote: > > Following KASAN BUG noticed on linux next 20211021 while booting qemu-arm64 > with allmodconfig. > [ 77.730367][ T5] Freed by task 1: > [ 77.732009][ T5] kasan_save_stack+0x30/0x80 > [ 77.734083][ T5] kasan_set_track+0x30/0x80 > [ 77.736085][ T5] kasan_set_free_info+0x34/0x80 > [ 77.738261][ T5] ____kasan_slab_free+0xfc/0x1c0 > [ 77.740433][ T5] __kasan_slab_free+0x3c/0x80 > [ 77.742518][ T5] slab_free_freelist_hook+0x1d4/0x2c0 > [ 77.744892][ T5] kfree+0x160/0x300 > [ 77.746618][ T5] blktrans_dev_release+0x64/0x100 > [ 77.748821][ T5] del_mtd_blktrans_dev+0x1c0/0x240 > [ 77.751079][ T5] mtdblock_remove_dev+0x28/0x80 > [ 77.753246][ T5] blktrans_notify_remove+0xa4/0x140 > [ 77.755507][ T5] del_mtd_device+0x84/0x1c0 > [ 77.757541][ T5] mtd_device_unregister+0x90/0xc0 > [ 77.759764][ T5] physmap_flash_remove+0x58/0x180 > [ 77.762012][ T5] platform_remove+0x48/0xc0 > [ 77.764032][ T5] __device_release_driver+0x1dc/0x340 > [ 77.766393][ T5] driver_detach+0x138/0x200 > [ 77.768396][ T5] bus_remove_driver+0x100/0x180 > [ 77.770554][ T5] driver_unregister+0x64/0xc0 > [ 77.772633][ T5] platform_driver_unregister+0x28/0x80 > [ 77.775042][ T5] physmap_init+0xc4/0xfc > [ 77.776994][ T5] do_one_initcall+0xb0/0x2c0 > [ 77.779028][ T5] do_initcalls+0x17c/0x244 > [ 77.781023][ T5] kernel_init_freeable+0x2d4/0x378 > [ 77.783269][ T5] kernel_init+0x34/0x180 > [ 77.785196][ T5] ret_from_fork+0x10/0x20 > [ 77.787135][ T5] > ... > full boot log link, > https://pastebin.com/xL5MYSD6 I think this is related to an earlier bug that Anders reported a while ago, see [1]. I had looked at it originally, and found that this probably a device that gets probed from CONFIG_MTD_PHYSMAP_COMPAT and then freed again immediately after we find the device does not exist, starting with commit dcb3e137ce9b ("[MTD] physmap: make physmap compat explicit"). It's not really the fault of CONFIG_MTD_PHYSMAP_COMPAT describing a nonexisting device, but instead it's something in the cleanup path. Arnd [1] https://lore.kernel.org/linux-mtd/CADYN=9Kjw_3cDGAvh9=+nNwdYof1kUPKG-SUOP5FsQhZ+gz62Q@xxxxxxxxxxxxxx/
