================================================================== BUG: KASAN: slab-use-after-free in gsm_cleanup_mux+0x81b/0x890 drivers/tty/n_gsm.c:3052 Read of size 4 at addr ffff88802556000c by task syz-executor415/5054 CPU: 0 PID: 5054 Comm: syz-executor415 Not tainted 6.5.0-rc5-next-20230807-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xc4/0x620 mm/kasan/report.c:475 kasan_report+0xda/0x110 mm/kasan/report.c:588 gsm_cleanup_mux+0x81b/0x890 drivers/tty/n_gsm.c:3052 gsm_config drivers/tty/n_gsm.c:3329 [inline] gsmld_ioctl+0x527/0x1660 drivers/tty/n_gsm.c:3738 tty_ioctl+0x706/0x1580 drivers/tty/tty_io.c:2793 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f133fff5869 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 71 19 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f133ff95168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f134007f418 RCX: 00007f133fff5869 RDX: 0000000020000040 RSI: 00000000404c4701 RDI: 0000000000000005 RBP: 00007f134007f410 R08: 00007ffd2b70fe47 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f134007f41c R13: 000000000000006e R14: 00007ffd2b70fd60 R15: 00007ffd2b70fe48 Allocated by task 5046: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:599 [inline] kzalloc include/linux/slab.h:720 [inline] gsm_dlci_alloc+0x4a/0x7b0 drivers/tty/n_gsm.c:2618 gsm_activate_mux drivers/tty/n_gsm.c:3102 [inline] gsm_config drivers/tty/n_gsm.c:3357 [inline] gsmld_ioctl+0x101b/0x1660 drivers/tty/n_gsm.c:3738 tty_ioctl+0x706/0x1580 drivers/tty/tty_io.c:2793 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 5046: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x15e/0x1b0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook+0x114/0x1e0 mm/slub.c:1826 slab_free mm/slub.c:3809 [inline] __kmem_cache_free+0xb8/0x2f0 mm/slub.c:3822 tty_port_destructor drivers/tty/tty_port.c:296 [inline] kref_put include/linux/kref.h:65 [inline] tty_port_put drivers/tty/tty_port.c:311 [inline] tty_port_put+0x15c/0x1c0 drivers/tty/tty_port.c:308 dlci_put drivers/tty/n_gsm.c:2681 [inline] gsm_dlci_release drivers/tty/n_gsm.c:2714 [inline] gsm_cleanup_mux+0x314/0x890 drivers/tty/n_gsm.c:3074 gsm_config drivers/tty/n_gsm.c:3329 [inline] gsmld_ioctl+0x527/0x1660 drivers/tty/n_gsm.c:3738 tty_ioctl+0x706/0x1580 drivers/tty/tty_io.c:2793 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff888025560000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 12 bytes inside of freed 2048-byte region [ffff888025560000, ffff888025560800) The buggy address belongs to the physical page: page:ffffea0000955800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x25560 head:ffffea0000955800 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000010200 ffff888012842000 dead000000000122 0000000000000000 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5046, tgid 5045 (syz-executor415), ts 43233549880, free_ts 43207513813 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2d2/0x350 mm/page_alloc.c:1567 prep_new_page mm/page_alloc.c:1574 [inline] get_page_from_freelist+0x10d7/0x31b0 mm/page_alloc.c:3253 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4509 alloc_pages+0x1a9/0x270 mm/mempolicy.c:2298 alloc_slab_page mm/slub.c:1870 [inline] allocate_slab+0x24e/0x380 mm/slub.c:2017 new_slab mm/slub.c:2070 [inline] ___slab_alloc+0x8bc/0x1570 mm/slub.c:3223 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3322 __slab_alloc_node mm/slub.c:3375 [inline] slab_alloc_node mm/slub.c:3468 [inline] __kmem_cache_alloc_node+0x137/0x350 mm/slub.c:3517 kmalloc_trace+0x25/0xe0 mm/slab_common.c:1114 kmalloc include/linux/slab.h:599 [inline] kzalloc include/linux/slab.h:720 [inline] gsm_dlci_alloc+0x4a/0x7b0 drivers/tty/n_gsm.c:2618 gsm_activate_mux drivers/tty/n_gsm.c:3102 [inline] gsm_config drivers/tty/n_gsm.c:3357 [inline] gsmld_ioctl+0x101b/0x1660 drivers/tty/n_gsm.c:3738 tty_ioctl+0x706/0x1580 drivers/tty/tty_io.c:2793 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1158 [inline] free_unref_page_prepare+0x508/0xb90 mm/page_alloc.c:2380 free_unref_page+0x33/0x3b0 mm/page_alloc.c:2475 __unfreeze_partials+0x21d/0x240 mm/slub.c:2655 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x18b/0x1d0 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x65/0x90 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook mm/slab.h:762 [inline] slab_alloc_node mm/slub.c:3478 [inline] __kmem_cache_alloc_node+0x19b/0x350 mm/slub.c:3517 kmalloc_trace+0x25/0xe0 mm/slab_common.c:1114 kmalloc include/linux/slab.h:599 [inline] kzalloc include/linux/slab.h:720 [inline] tomoyo_print_bprm security/tomoyo/audit.c:26 [inline] tomoyo_init_log+0xce5/0x2130 security/tomoyo/audit.c:264 tomoyo_supervisor+0x30c/0xea0 security/tomoyo/common.c:2089 tomoyo_audit_env_log security/tomoyo/environ.c:36 [inline] tomoyo_env_perm+0x18f/0x200 security/tomoyo/environ.c:63 tomoyo_environ security/tomoyo/domain.c:672 [inline] tomoyo_find_next_domain+0xef6/0x2020 security/tomoyo/domain.c:878 tomoyo_bprm_check_security security/tomoyo/tomoyo.c:101 [inline] tomoyo_bprm_check_security+0x12d/0x1d0 security/tomoyo/tomoyo.c:91 security_bprm_check+0x6a/0xe0 security/security.c:1103 search_binary_handler fs/exec.c:1727 [inline] exec_binprm fs/exec.c:1781 [inline] bprm_execve fs/exec.c:1856 [inline] bprm_execve+0x74d/0x1a50 fs/exec.c:1812 do_execveat_common.isra.0+0x5d3/0x740 fs/exec.c:1964 Memory state around the buggy address: ffff88802555ff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88802555ff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888025560000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888025560080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888025560100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================