================================================================== BUG: KASAN: slab-use-after-free in update_tty_status drivers/net/caif/caif_serial.c:90 [inline] BUG: KASAN: slab-use-after-free in handle_tx+0x5dc/0x630 drivers/net/caif/caif_serial.c:223 Read of size 1 at addr ffff888050e65490 by task aoe_tx0/1422 CPU: 1 UID: 0 PID: 1422 Comm: aoe_tx0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 update_tty_status drivers/net/caif/caif_serial.c:90 [inline] handle_tx+0x5dc/0x630 drivers/net/caif/caif_serial.c:223 __netdev_start_xmit include/linux/netdevice.h:5222 [inline] netdev_start_xmit include/linux/netdevice.h:5231 [inline] xmit_one net/core/dev.c:3839 [inline] dev_hard_start_xmit+0x97/0x740 net/core/dev.c:3855 __dev_queue_xmit+0xa46/0x4490 net/core/dev.c:4725 dev_queue_xmit include/linux/netdevice.h:3361 [inline] tx+0xcc/0x190 drivers/block/aoe/aoenet.c:62 kthread+0x1e1/0x3e0 drivers/block/aoe/aoecmd.c:1241 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 6288: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:388 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:405 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] alloc_tty_struct+0x96/0x8c0 drivers/tty/tty_io.c:3102 tty_init_dev.part.0+0x1e/0x500 drivers/tty/tty_io.c:1400 tty_init_dev include/linux/err.h:70 [inline] tty_open_by_driver drivers/tty/tty_io.c:2073 [inline] tty_open+0xa50/0xf90 drivers/tty/tty_io.c:2120 chrdev_open+0x234/0x6a0 fs/char_dev.c:414 do_dentry_open+0x982/0x1530 fs/open.c:965 vfs_open+0x82/0x3f0 fs/open.c:1095 do_open fs/namei.c:3887 [inline] path_openat+0x1de4/0x2cb0 fs/namei.c:4046 do_filp_open+0x20b/0x470 fs/namei.c:4073 do_sys_openat2+0x11b/0x1d0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_compat_sys_openat fs/open.c:1512 [inline] __se_compat_sys_openat fs/open.c:1510 [inline] __ia32_compat_sys_openat+0x16d/0x210 fs/open.c:1510 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x7c/0x3a0 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Freed by task 5985: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x60/0x70 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2417 [inline] slab_free mm/slub.c:4680 [inline] kfree+0x2b4/0x4d0 mm/slub.c:4879 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Last potentially related work creation: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:548 insert_work+0x36/0x230 kernel/workqueue.c:2184 __queue_work+0x97e/0x1160 kernel/workqueue.c:2339 queue_work_on+0x1a4/0x1f0 kernel/workqueue.c:2390 kref_put include/linux/kref.h:65 [inline] tty_kref_put drivers/tty/tty_io.c:1557 [inline] tty_kref_put drivers/tty/tty_io.c:1554 [inline] release_tty+0x4de/0x5d0 drivers/tty/tty_io.c:1593 tty_release_struct+0xb7/0xe0 drivers/tty/tty_io.c:1692 tty_release+0xe2d/0x1430 drivers/tty/tty_io.c:1852 __fput+0x402/0xb70 fs/file_table.c:468 task_work_run+0x14d/0x240 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x86f/0x2bf0 kernel/exit.c:961 do_group_exit+0xd3/0x2a0 kernel/exit.c:1102 get_signal+0x2673/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] __do_fast_syscall_32+0x2ac/0x3a0 arch/x86/entry/syscall_32.c:309 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e The buggy address belongs to the object at ffff888050e65000 which belongs to the cache kmalloc-cg-2k of size 2048 The buggy address is located 1168 bytes inside of freed 2048-byte region [ffff888050e65000, ffff888050e65800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x50e60 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88806c2e6c01 anon flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 04fff00000000040 ffff88801b84c140 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000080008 00000000f5000000 ffff88806c2e6c01 head: 04fff00000000040 ffff88801b84c140 0000000000000000 dead000000000001 head: 0000000000000000 0000000000080008 00000000f5000000 ffff88806c2e6c01 head: 04fff00000000003 ffffea0001439801 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6278, tgid 6276 (syz.3.49), ts 60607950310, free_ts 60568745788 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x132b/0x38e0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:5148 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2487 [inline] allocate_slab mm/slub.c:2655 [inline] new_slab+0x247/0x330 mm/slub.c:2709 ___slab_alloc+0xcf2/0x1740 mm/slub.c:3891 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3981 __slab_alloc_node mm/slub.c:4056 [inline] slab_alloc_node mm/slub.c:4217 [inline] __kmalloc_cache_noprof+0xfb/0x3e0 mm/slub.c:4391 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] copy_verifier_state+0xbad/0xfb0 kernel/bpf/verifier.c:1769 push_stack+0x1ca/0x370 kernel/bpf/verifier.c:2112 check_cond_jmp_op+0xaf1/0x72d0 kernel/bpf/verifier.c:16761 do_check_insn kernel/bpf/verifier.c:19956 [inline] do_check kernel/bpf/verifier.c:20093 [inline] do_check_common+0xa13e/0xb410 kernel/bpf/verifier.c:23260 do_check_main kernel/bpf/verifier.c:23343 [inline] bpf_check+0x8763/0xc4d0 kernel/bpf/verifier.c:24703 bpf_prog_load+0xe41/0x2490 kernel/bpf/syscall.c:2979 __sys_bpf+0x4a3f/0x4de0 kernel/bpf/syscall.c:6029 __do_sys_bpf kernel/bpf/syscall.c:6139 [inline] __se_sys_bpf kernel/bpf/syscall.c:6137 [inline] __ia32_sys_bpf+0x76/0xe0 kernel/bpf/syscall.c:6137 page last free pid 6271 tgid 6270 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0x7d5/0x10f0 mm/page_alloc.c:2895 bpf_check+0x909/0xc4d0 kernel/bpf/verifier.c:24838 bpf_prog_load+0xe41/0x2490 kernel/bpf/syscall.c:2979 __sys_bpf+0x4a3f/0x4de0 kernel/bpf/syscall.c:6029 __do_sys_bpf kernel/bpf/syscall.c:6139 [inline] __se_sys_bpf kernel/bpf/syscall.c:6137 [inline] __ia32_sys_bpf+0x76/0xe0 kernel/bpf/syscall.c:6137 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x7c/0x3a0 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Memory state around the buggy address: ffff888050e65380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888050e65400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888050e65480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888050e65500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888050e65580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================