==================================================================
BUG: KASAN: use-after-free in gsm_cleanup_mux+0x700/0x7d8 drivers/tty/n_gsm.c:2491
Read of size 4 at addr ffff0000c464a00c by task syz-executor413/4221

CPU: 0 PID: 4221 Comm: syz-executor413 Not tainted 6.1.30-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023
Call trace:
 dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:284 [inline]
 print_report+0x174/0x4c0 mm/kasan/report.c:395
 kasan_report+0xd4/0x130 mm/kasan/report.c:495
 __asan_report_load4_noabort+0x2c/0x38 mm/kasan/report_generic.c:350
 gsm_cleanup_mux+0x700/0x7d8 drivers/tty/n_gsm.c:2491
 gsm_config drivers/tty/n_gsm.c:2754 [inline]
 gsmld_ioctl+0x9d4/0x1384 drivers/tty/n_gsm.c:3117
 tty_ioctl+0x924/0xd8c drivers/tty/tty_io.c:2782
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

Allocated by task 4216:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4c/0x80 mm/kasan/common.c:52
 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:505
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0xac/0xc4 mm/kasan/common.c:383
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 kmalloc_trace+0x7c/0x94 mm/slab_common.c:1050
 kmalloc include/linux/slab.h:553 [inline]
 kzalloc include/linux/slab.h:689 [inline]
 gsm_dlci_alloc+0x60/0x340 drivers/tty/n_gsm.c:2064
 gsm_activate_mux+0x30/0x268 drivers/tty/n_gsm.c:2538
 gsm_config drivers/tty/n_gsm.c:2778 [inline]
 gsmld_ioctl+0xbc0/0x1384 drivers/tty/n_gsm.c:3117
 tty_ioctl+0x924/0xd8c drivers/tty/tty_io.c:2782
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

Freed by task 4216:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4c/0x80 mm/kasan/common.c:52
 kasan_save_free_info+0x38/0x5c mm/kasan/generic.c:516
 ____kasan_slab_free+0x144/0x1c0 mm/kasan/common.c:236
 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:244
 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+0x2c0/0x4b4 mm/slub.c:3674
 kfree+0xcc/0x1b8 mm/slab_common.c:1007
 gsm_dlci_free+0x11c/0x168 drivers/tty/n_gsm.c:2110
 tty_port_destructor drivers/tty/tty_port.c:296 [inline]
 kref_put include/linux/kref.h:65 [inline]
 tty_port_put+0xfc/0x190 drivers/tty/tty_port.c:311
 dlci_put drivers/tty/n_gsm.c:2120 [inline]
 gsm_dlci_release drivers/tty/n_gsm.c:2153 [inline]
 gsm_cleanup_mux+0x48c/0x7d8 drivers/tty/n_gsm.c:2512
 gsm_config drivers/tty/n_gsm.c:2754 [inline]
 gsmld_ioctl+0x9d4/0x1384 drivers/tty/n_gsm.c:3117
 tty_ioctl+0x924/0xd8c drivers/tty/tty_io.c:2782
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

The buggy address belongs to the object at ffff0000c464a000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 12 bytes inside of
 2048-byte region [ffff0000c464a000, ffff0000c464a800)

The buggy address belongs to the physical page:
page:00000000e54018b5 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x104648
head:00000000e54018b5 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000010200 0000000000000000 dead000000000001 ffff0000c0002900
raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000c4649f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff0000c4649f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff0000c464a000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff0000c464a080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff0000c464a100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
================================================================================
UBSAN: array-index-out-of-bounds in kernel/locking/qspinlock.c:131:9
index 1163 is out of range for type 'unsigned long[8]'
CPU: 0 PID: 4221 Comm: syz-executor413 Tainted: G    B              6.1.30-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023
Call trace:
 dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 dump_stack+0x1c/0x58 lib/dump_stack.c:113
 ubsan_epilogue lib/ubsan.c:151 [inline]
 __ubsan_handle_out_of_bounds+0xfc/0x148 lib/ubsan.c:282
 decode_tail kernel/locking/qspinlock.c:131 [inline]
 queued_spin_lock_slowpath+0x9fc/0xe48 kernel/locking/qspinlock.c:471
 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
 do_raw_spin_lock+0x330/0x358 kernel/locking/spinlock_debug.c:115
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
 _raw_spin_lock_irqsave+0x74/0xb4 kernel/locking/spinlock.c:162
 gsm_send+0x31c/0x604 drivers/tty/n_gsm.c:725
 gsm_command drivers/tty/n_gsm.c:789 [inline]
 gsm_dlci_begin_close drivers/tty/n_gsm.c:1933 [inline]
 gsm_cleanup_mux+0x1a0/0x7d8 drivers/tty/n_gsm.c:2492
 gsm_config drivers/tty/n_gsm.c:2754 [inline]
 gsmld_ioctl+0x9d4/0x1384 drivers/tty/n_gsm.c:3117
 tty_ioctl+0x924/0xd8c drivers/tty/tty_io.c:2782
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581
================================================================================