================================================================== BUG: KASAN: use-after-free in gsm_cleanup_mux+0x824/0x910 drivers/tty/n_gsm.c:2491 Read of size 4 at addr ffff888016ae100c by task syz-executor292/3549 CPU: 1 PID: 3549 Comm: syz-executor292 Not tainted 6.1.35-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15f/0x4f0 mm/kasan/report.c:395 kasan_report+0x136/0x160 mm/kasan/report.c:495 gsm_cleanup_mux+0x824/0x910 drivers/tty/n_gsm.c:2491 gsm_config drivers/tty/n_gsm.c:2754 [inline] gsmld_ioctl+0xab7/0x15a0 drivers/tty/n_gsm.c:3117 tty_ioctl+0x88e/0xbd0 drivers/tty/tty_io.c:2782 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f63eb2ddc69 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f63eb26e318 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f63eb3654d8 RCX: 00007f63eb2ddc69 RDX: 0000000020000040 RSI: 00000000404c4701 RDI: 0000000000000004 RBP: 00007f63eb3654d0 R08: 00007f63eb26e700 R09: 0000000000000000 R10: 00007f63eb26e700 R11: 0000000000000246 R12: 00007f63eb33308c R13: 00007fffde92073f R14: 00007f63eb26e400 R15: 0000000000022000 Allocated by task 3543: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x97/0xb0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:553 [inline] kzalloc include/linux/slab.h:689 [inline] gsm_dlci_alloc+0x53/0x3a0 drivers/tty/n_gsm.c:2064 gsm_activate_mux+0x1c/0x290 drivers/tty/n_gsm.c:2538 gsm_config drivers/tty/n_gsm.c:2778 [inline] gsmld_ioctl+0xd66/0x15a0 drivers/tty/n_gsm.c:3117 tty_ioctl+0x88e/0xbd0 drivers/tty/tty_io.c:2782 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 3543: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook mm/slub.c:1750 [inline] slab_free mm/slub.c:3661 [inline] __kmem_cache_free+0x25c/0x3c0 mm/slub.c:3674 dlci_put drivers/tty/n_gsm.c:2120 [inline] gsm_dlci_release drivers/tty/n_gsm.c:2153 [inline] gsm_cleanup_mux+0x57e/0x910 drivers/tty/n_gsm.c:2512 gsm_config drivers/tty/n_gsm.c:2754 [inline] gsmld_ioctl+0xab7/0x15a0 drivers/tty/n_gsm.c:3117 tty_ioctl+0x88e/0xbd0 drivers/tty/tty_io.c:2782 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb0/0xc0 mm/kasan/generic.c:486 call_rcu+0x163/0xa10 kernel/rcu/tree.c:2799 netlink_release+0x1384/0x17f0 net/netlink/af_netlink.c:817 __sock_release net/socket.c:652 [inline] sock_close+0xcd/0x230 net/socket.c:1370 __fput+0x3b7/0x890 fs/file_table.c:320 task_work_run+0x246/0x300 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xd9/0x100 kernel/entry/common.c:171 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:297 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff888016ae1000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 12 bytes inside of 2048-byte region [ffff888016ae1000, ffff888016ae1800) The buggy address belongs to the physical page: page:ffffea00005ab800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x16ae0 head:ffffea00005ab800 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888012442000 raw: 0000000000000000 0000000000080008 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 2421548043, free_ts 0 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2533 prep_new_page mm/page_alloc.c:2540 [inline] get_page_from_freelist+0x32ed/0x3480 mm/page_alloc.c:4292 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5559 alloc_page_interleave+0x22/0x1c0 mm/mempolicy.c:2113 alloc_slab_page+0x6a/0x150 mm/slub.c:1794 allocate_slab mm/slub.c:1939 [inline] new_slab+0x84/0x2d0 mm/slub.c:1992 ___slab_alloc+0xa71/0x1080 mm/slub.c:3180 __slab_alloc mm/slub.c:3279 [inline] slab_alloc_node mm/slub.c:3364 [inline] __kmem_cache_alloc_node+0x19f/0x260 mm/slub.c:3437 kmalloc_trace+0x26/0xe0 mm/slab_common.c:1045 kmalloc include/linux/slab.h:553 [inline] kzalloc include/linux/slab.h:689 [inline] acpi_os_allocate_zeroed include/acpi/platform/aclinuxex.h:57 [inline] acpi_ds_create_walk_state+0xff/0x2a0 drivers/acpi/acpica/dswstate.c:518 acpi_ds_auto_serialize_method+0xe3/0x240 drivers/acpi/acpica/dsmethod.c:81 acpi_ds_init_one_object+0x1b7/0x360 drivers/acpi/acpica/dsinit.c:110 acpi_ns_walk_namespace+0x28c/0x4e0 acpi_ds_initialize_objects+0x195/0x2a0 drivers/acpi/acpica/dsinit.c:189 acpi_ns_load_table+0xf5/0x120 drivers/acpi/acpica/nsload.c:106 acpi_tb_load_namespace+0x289/0x6c0 drivers/acpi/acpica/tbxfload.c:158 page_owner free stack trace missing Memory state around the buggy address: ffff888016ae0f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888016ae0f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888016ae1000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888016ae1080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888016ae1100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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