================================================================== BUG: KASAN: slab-use-after-free in tty_write_room+0x7d/0x90 drivers/tty/tty_ioctl.c:68 Read of size 8 at addr ffff888050c46020 by task aoe_tx0/1421 CPU: 3 UID: 0 PID: 1421 Comm: aoe_tx0 Not tainted 6.15.0-rc7-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:408 [inline] print_report+0xc3/0x670 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 tty_write_room+0x7d/0x90 drivers/tty/tty_ioctl.c:68 handle_tx+0x14f/0x630 drivers/net/caif/caif_serial.c:212 __netdev_start_xmit include/linux/netdevice.h:5204 [inline] netdev_start_xmit include/linux/netdevice.h:5213 [inline] xmit_one net/core/dev.c:3776 [inline] dev_hard_start_xmit+0x93/0x740 net/core/dev.c:3792 __dev_queue_xmit+0x7eb/0x43e0 net/core/dev.c:4629 dev_queue_xmit include/linux/netdevice.h:3350 [inline] tx+0xcc/0x190 drivers/block/aoe/aoenet.c:62 kthread+0x1e4/0x3e0 drivers/block/aoe/aoecmd.c:1237 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 8848: 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:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 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:3115 tty_init_dev.part.0+0x1e/0x500 drivers/tty/tty_io.c:1409 tty_init_dev include/linux/err.h:70 [inline] tty_open_by_driver drivers/tty/tty_io.c:2082 [inline] tty_open+0xa50/0xf90 drivers/tty/tty_io.c:2129 chrdev_open+0x234/0x6a0 fs/char_dev.c:414 do_dentry_open+0x744/0x1c10 fs/open.c:956 vfs_open+0x82/0x3f0 fs/open.c:1086 do_open fs/namei.c:3880 [inline] path_openat+0x1e5e/0x2d40 fs/namei.c:4039 do_filp_open+0x20b/0x470 fs/namei.c:4066 do_sys_openat2+0x11b/0x1d0 fs/open.c:1429 do_sys_open fs/open.c:1444 [inline] __do_sys_openat fs/open.c:1460 [inline] __se_sys_openat fs/open.c:1455 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1455 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5973: 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:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2380 [inline] slab_free mm/slub.c:4642 [inline] kfree+0x2b6/0x4d0 mm/slub.c:4841 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 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+0xb8/0xd0 mm/kasan/generic.c:548 insert_work+0x36/0x230 kernel/workqueue.c:2183 __queue_work+0x97e/0x10f0 kernel/workqueue.c:2341 queue_work_on+0x1a4/0x1f0 kernel/workqueue.c:2392 kref_put include/linux/kref.h:65 [inline] tty_kref_put drivers/tty/tty_io.c:1566 [inline] tty_kref_put drivers/tty/tty_io.c:1563 [inline] release_tty+0x4de/0x5d0 drivers/tty/tty_io.c:1602 tty_release_struct+0xb7/0xe0 drivers/tty/tty_io.c:1701 tty_release+0xe2d/0x1430 drivers/tty/tty_io.c:1861 __fput+0x3ff/0xb70 fs/file_table.c:465 task_work_run+0x150/0x240 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xafb/0x2c30 kernel/exit.c:953 do_group_exit+0xd3/0x2a0 kernel/exit.c:1102 get_signal+0x2673/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x260 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888050c46000 which belongs to the cache kmalloc-cg-2k of size 2048 The buggy address is located 32 bytes inside of freed 2048-byte region [ffff888050c46000, ffff888050c46800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888050c45000 pfn:0x50c40 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88804d353401 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000240 ffff88801b44c140 ffffea0000c57010 ffffea00013de610 raw: ffff888050c45000 0000000000080007 00000000f5000000 ffff88804d353401 head: 00fff00000000240 ffff88801b44c140 ffffea0000c57010 ffffea00013de610 head: ffff888050c45000 0000000000080007 00000000f5000000 ffff88804d353401 head: 00fff00000000003 ffffea0001431001 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 8305, tgid 8304 (syz.5.685), ts 89714108237, free_ts 89665112802 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1714 prep_new_page mm/page_alloc.c:1722 [inline] get_page_from_freelist+0x135c/0x3920 mm/page_alloc.c:3684 __alloc_frozen_pages_noprof+0x263/0x23a0 mm/page_alloc.c:4966 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2301 alloc_slab_page mm/slub.c:2450 [inline] allocate_slab mm/slub.c:2618 [inline] new_slab+0x244/0x340 mm/slub.c:2672 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3858 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3948 __slab_alloc_node mm/slub.c:4023 [inline] slab_alloc_node mm/slub.c:4184 [inline] __do_kmalloc_node mm/slub.c:4326 [inline] __kmalloc_node_noprof+0x2ed/0x500 mm/slub.c:4333 kmalloc_node_noprof include/linux/slab.h:932 [inline] __bpf_map_area_alloc+0x162/0x190 kernel/bpf/syscall.c:390 htab_map_alloc+0x456/0x1540 kernel/bpf/hashtab.c:511 map_create+0x592/0x1db0 kernel/bpf/syscall.c:1476 __sys_bpf+0x47cc/0x4d80 kernel/bpf/syscall.c:5816 __do_sys_bpf kernel/bpf/syscall.c:5941 [inline] __se_sys_bpf kernel/bpf/syscall.c:5939 [inline] __x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:5939 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 8303 tgid 8302 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1258 [inline] __free_frozen_pages+0x69d/0xff0 mm/page_alloc.c:2721 __folio_put+0x329/0x450 mm/swap.c:112 bpf_check+0x908/0xbbc0 kernel/bpf/verifier.c:24168 bpf_prog_load+0xe41/0x2490 kernel/bpf/syscall.c:2971 __sys_bpf+0x433c/0x4d80 kernel/bpf/syscall.c:5834 __do_sys_bpf kernel/bpf/syscall.c:5941 [inline] __se_sys_bpf kernel/bpf/syscall.c:5939 [inline] __x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:5939 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888050c45f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888050c45f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888050c46000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888050c46080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888050c46100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================