On 11/1/18 6:50 PM, Ming Lei wrote: > brd_free() may be called in failure path on one brd instance which > disk isn't added yet, so release handler of gendisk may free the > associated request_queue early and causes the following use-after-free[1]. > > This patch fixes this issue by associating gendisk with request_queue > just before adding disk. > > [1] KASAN: use-after-free Read in del_timer_syncNon-volatile memory driver v1.3 > Linux agpgart interface v0.103 > [drm] Initialized vgem 1.0.0 20120112 for virtual device on minor 0 > usbcore: registered new interface driver udl > ================================================================== > BUG: KASAN: use-after-free in __lock_acquire+0x36d9/0x4c20 > kernel/locking/lockdep.c:3218 > Read of size 8 at addr ffff8801d1b6b540 by task swapper/0/1 > > CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.0+ #88 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x244/0x39d lib/dump_stack.c:113 > print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256 > kasan_report_error mm/kasan/report.c:354 [inline] > kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412 > __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 > __lock_acquire+0x36d9/0x4c20 kernel/locking/lockdep.c:3218 > lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3844 > del_timer_sync+0xb7/0x270 kernel/time/timer.c:1283 > blk_cleanup_queue+0x413/0x710 block/blk-core.c:809 > brd_free+0x5d/0x71 drivers/block/brd.c:422 > brd_init+0x2eb/0x393 drivers/block/brd.c:518 > do_one_initcall+0x145/0x957 init/main.c:890 > do_initcall_level init/main.c:958 [inline] > do_initcalls init/main.c:966 [inline] > do_basic_setup init/main.c:984 [inline] > kernel_init_freeable+0x5c6/0x6b9 init/main.c:1148 > kernel_init+0x11/0x1ae init/main.c:1068 > ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:350 > > Reported-by: syzbot+3701447012fe951dabb2@xxxxxxxxxxxxxxxxxxxxxxxxx > Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx> Replaced the other patch with this one. -- Jens Axboe
