================================================================== BUG: KASAN: use-after-free in sl_sync drivers/net/slip/slip.c:730 [inline] BUG: KASAN: use-after-free in slip_open+0xed2/0x1210 drivers/net/slip/slip.c:806 Read of size 8 at addr ffff88802fb66c88 by task syz-executor.1/8507 CPU: 1 PID: 8507 Comm: syz-executor.1 Not tainted 6.0.0-rc6-next-20220923-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15e/0x45d mm/kasan/report.c:395 kasan_report+0xbb/0x1f0 mm/kasan/report.c:495 sl_sync drivers/net/slip/slip.c:730 [inline] slip_open+0xed2/0x1210 drivers/net/slip/slip.c:806 tty_ldisc_open+0x9b/0x110 drivers/tty/tty_ldisc.c:433 tty_set_ldisc+0x2f1/0x680 drivers/tty/tty_ldisc.c:558 tiocsetd drivers/tty/tty_io.c:2433 [inline] tty_ioctl+0xe20/0x15d0 drivers/tty/tty_io.c:2714 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+0x193/0x200 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7ff423e8b5a9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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:00007ff4250c7168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ff423fabf80 RCX: 00007ff423e8b5a9 RDX: 0000000020000080 RSI: 0000000000005423 RDI: 0000000000000003 RBP: 00007ff423ee6580 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffed23060df R14: 00007ff4250c7300 R15: 0000000000022000 Allocated by task 8489: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:45 kasan_set_track+0x21/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:371 [inline] ____kasan_kmalloc mm/kasan/common.c:330 [inline] __kasan_kmalloc+0xa1/0xb0 mm/kasan/common.c:380 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slab_common.c:934 [inline] __kmalloc_node+0x57/0xc0 mm/slab_common.c:941 kmalloc_node include/linux/slab.h:585 [inline] kvmalloc_node+0x3e/0x190 mm/util.c:581 kvmalloc include/linux/slab.h:712 [inline] kvzalloc include/linux/slab.h:720 [inline] alloc_netdev_mqs+0x98/0x1180 net/core/dev.c:10601 sl_alloc drivers/net/slip/slip.c:756 [inline] slip_open+0x36d/0x1210 drivers/net/slip/slip.c:817 tty_ldisc_open+0x9b/0x110 drivers/tty/tty_ldisc.c:433 tty_set_ldisc+0x2f1/0x680 drivers/tty/tty_ldisc.c:558 tiocsetd drivers/tty/tty_io.c:2433 [inline] tty_ioctl+0xe20/0x15d0 drivers/tty/tty_io.c:2714 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+0x193/0x200 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 8488: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:45 kasan_set_track+0x21/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2a/0x40 mm/kasan/generic.c:511 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1669 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1695 slab_free mm/slub.c:3599 [inline] __kmem_cache_free+0xab/0x3b0 mm/slub.c:3612 kvfree+0x42/0x50 mm/util.c:623 device_release+0x9f/0x240 drivers/base/core.c:2330 kobject_cleanup lib/kobject.c:673 [inline] kobject_release lib/kobject.c:704 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1be/0x4c0 lib/kobject.c:721 netdev_run_todo+0x75e/0x1100 net/core/dev.c:10383 slip_close+0x161/0x1c0 drivers/net/slip/slip.c:906 tty_ldisc_close+0x110/0x190 drivers/tty/tty_ldisc.c:456 tty_ldisc_kill+0x94/0x150 drivers/tty/tty_ldisc.c:608 tty_ldisc_release+0x1ef/0x2a0 drivers/tty/tty_ldisc.c:776 tty_release_struct+0x20/0xe0 drivers/tty/tty_io.c:1694 tty_release+0xc70/0x1200 drivers/tty/tty_io.c:1865 __fput+0x27c/0xa90 fs/file_table.c:320 task_work_run+0x16b/0x270 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:296 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff88802fb66000 which belongs to the cache kmalloc-cg-4k of size 4096 The buggy address is located 3208 bytes inside of 4096-byte region [ffff88802fb66000, ffff88802fb67000) The buggy address belongs to the physical page: page:ffffea0000bed800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2fb60 head:ffffea0000bed800 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88801be82001 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffff88801184c280 dead000000040004 0000000000000000 raw: 0000000000000000 dead000000000001 00000001ffffffff ffff88801be82001 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d60c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 4054, tgid 4052 (syz-executor.3), ts 244686615747, free_ts 244473240394 prep_new_page mm/page_alloc.c:2538 [inline] get_page_from_freelist+0x1092/0x2d20 mm/page_alloc.c:4287 __alloc_pages+0x1c7/0x5a0 mm/page_alloc.c:5546 alloc_pages+0x1a6/0x270 mm/mempolicy.c:2280 alloc_slab_page mm/slub.c:1739 [inline] allocate_slab+0x213/0x300 mm/slub.c:1884 new_slab mm/slub.c:1937 [inline] ___slab_alloc+0xac1/0x1430 mm/slub.c:3119 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3217 slab_alloc_node mm/slub.c:3302 [inline] __kmem_cache_alloc_node+0x18a/0x3d0 mm/slub.c:3375 __do_kmalloc_node mm/slab_common.c:933 [inline] __kmalloc_node+0x47/0xc0 mm/slab_common.c:941 kmalloc_node include/linux/slab.h:585 [inline] kvmalloc_node+0x3e/0x190 mm/util.c:581 kvmalloc include/linux/slab.h:712 [inline] kvzalloc include/linux/slab.h:720 [inline] alloc_netdev_mqs+0x98/0x1180 net/core/dev.c:10601 ip6_tnl_init_net+0x213/0x890 net/ipv6/ip6_tunnel.c:2273 ops_init+0xaf/0x470 net/core/net_namespace.c:135 setup_net+0x5d1/0xc50 net/core/net_namespace.c:326 copy_net_ns+0x318/0x760 net/core/net_namespace.c:472 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 copy_namespaces+0x391/0x450 kernel/nsproxy.c:178 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1458 [inline] free_pcp_prepare+0x65c/0xd90 mm/page_alloc.c:1508 free_unref_page_prepare mm/page_alloc.c:3386 [inline] free_unref_page+0x19/0x4d0 mm/page_alloc.c:3482 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2532 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x62/0x80 mm/kasan/common.c:302 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slab.h:754 [inline] slab_alloc_node mm/slub.c:3336 [inline] __kmem_cache_alloc_node+0x2d2/0x3d0 mm/slub.c:3375 __do_kmalloc_node mm/slab_common.c:933 [inline] __kmalloc+0x44/0xc0 mm/slab_common.c:947 kmalloc include/linux/slab.h:564 [inline] tomoyo_realpath_from_path+0xbf/0x600 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x21b/0x400 security/tomoyo/file.c:822 security_inode_getattr+0xcf/0x140 security/security.c:1345 vfs_getattr fs/stat.c:158 [inline] vfs_statx+0x16e/0x430 fs/stat.c:233 vfs_fstatat+0x8c/0xb0 fs/stat.c:267 vfs_lstat include/linux/fs.h:3285 [inline] __do_sys_newlstat+0x8e/0x110 fs/stat.c:423 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff88802fb66b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802fb66c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88802fb66c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802fb66d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802fb66d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================