================================================================== BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:587 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock+0xfe/0xd70 kernel/locking/mutex.c:752 Read of size 8 at addr ffff888057f46408 by task jffs2_gcd_mtd0/5606 CPU: 1 PID: 5606 Comm: jffs2_gcd_mtd0 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 __mutex_lock_common kernel/locking/mutex.c:587 [inline] __mutex_lock+0xfe/0xd70 kernel/locking/mutex.c:752 jffs2_erase_pending_blocks+0x275/0x2740 fs/jffs2/erase.c:148 jffs2_garbage_collect_pass+0x6b3/0x2120 fs/jffs2/gc.c:253 jffs2_garbage_collect_thread+0x651/0x6e0 fs/jffs2/background.c:155 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 Allocated by task 5603: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] kmalloc_trace+0x1db/0x360 mm/slub.c:3997 kmalloc include/linux/slab.h:628 [inline] kzalloc include/linux/slab.h:749 [inline] jffs2_init_fs_context+0x4f/0xc0 fs/jffs2/super.c:313 alloc_fs_context+0x68a/0x800 fs/fs_context.c:318 do_new_mount+0x160/0xb40 fs/namespace.c:3331 do_mount fs/namespace.c:3692 [inline] __do_sys_mount fs/namespace.c:3898 [inline] __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3875 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 Freed by task 5070: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 poison_slab_object+0xa6/0xe0 mm/kasan/common.c:240 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2106 [inline] slab_free mm/slub.c:4280 [inline] kfree+0x14a/0x380 mm/slub.c:4390 deactivate_locked_super+0xc4/0x130 fs/super.c:472 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1267 task_work_run+0x24f/0x310 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:108 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:201 [inline] syscall_exit_to_user_mode+0x168/0x360 kernel/entry/common.c:212 do_syscall_64+0x10a/0x240 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x6d/0x75 The buggy address belongs to the object at ffff888057f46000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1032 bytes inside of freed 4096-byte region [ffff888057f46000, ffff888057f47000) The buggy address belongs to the physical page: page:ffffea00015fd000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x57f40 head:ffffea00015fd000 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888014c42140 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5142, tgid 5142 (kworker/0:6), ts 68285239191, free_ts 14204308371 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1533 prep_new_page mm/page_alloc.c:1540 [inline] get_page_from_freelist+0x33ea/0x3580 mm/page_alloc.c:3311 __alloc_pages+0x256/0x680 mm/page_alloc.c:4569 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] alloc_slab_page+0x5f/0x160 mm/slub.c:2175 allocate_slab mm/slub.c:2338 [inline] new_slab+0x84/0x2f0 mm/slub.c:2391 ___slab_alloc+0xc73/0x1260 mm/slub.c:3525 __slab_alloc mm/slub.c:3610 [inline] __slab_alloc_node mm/slub.c:3663 [inline] slab_alloc_node mm/slub.c:3835 [inline] __do_kmalloc_node mm/slub.c:3965 [inline] __kmalloc_node_track_caller+0x2d6/0x4e0 mm/slub.c:3986 kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:599 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:668 alloc_skb include/linux/skbuff.h:1318 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x254/0xaa0 drivers/net/netdevsim/dev.c:850 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 page last free pid 1 tgid 1 stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1140 [inline] free_unref_page_prepare+0x95d/0xa80 mm/page_alloc.c:2346 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2486 free_contig_range+0x9e/0x160 mm/page_alloc.c:6547 destroy_args+0x8a/0x890 mm/debug_vm_pgtable.c:1036 debug_vm_pgtable+0x4be/0x550 mm/debug_vm_pgtable.c:1416 do_one_initcall+0x238/0x830 init/main.c:1241 do_initcall_level+0x157/0x210 init/main.c:1303 do_initcalls+0x3f/0x80 init/main.c:1319 kernel_init_freeable+0x435/0x5d0 init/main.c:1550 kernel_init+0x1d/0x2a0 init/main.c:1439 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 Memory state around the buggy address: ffff888057f46300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888057f46380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888057f46400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888057f46480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888057f46500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================