[U] ================================================================== BUG: KASAN: use-after-free in sixpack_close+0x236/0x270 drivers/net/hamradio/6pack.c:678 Read of size 8 at addr ffff8880296bcc90 by task syz-executor.5/27306 CPU: 1 PID: 27306 Comm: syz-executor.5 Not tainted 5.16.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0x8d/0x320 mm/kasan/report.c:247 __kasan_report mm/kasan/report.c:433 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:450 sixpack_close+0x236/0x270 drivers/net/hamradio/6pack.c:678 tty_ldisc_close+0x110/0x190 drivers/tty/tty_ldisc.c:474 tty_ldisc_kill+0x94/0x150 drivers/tty/tty_ldisc.c:629 tty_ldisc_release+0x154/0x2a0 drivers/tty/tty_ldisc.c:803 tty_release_struct+0x20/0xe0 drivers/tty/tty_io.c:1706 tty_release+0xc70/0x1200 drivers/tty/tty_io.c:1878 __fput+0x286/0x9f0 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:175 [inline] exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7eff36f8272b Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44 RSP: 002b:00007fff58bcf750 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000006 RCX: 00007eff36f8272b RDX: 00007eff370e7470 RSI: ffffffff895238d1 RDI: 0000000000000005 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000001b2d82555c R10: 00000000000017be R11: 0000000000000293 R12: 00000000000c0904 R13: 00000000000003e8 R14: 00007eff370e2f60 R15: 00000000000c087f Allocated by task 27318: kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] ____kasan_kmalloc mm/kasan/common.c:472 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:522 kmalloc_node include/linux/slab.h:613 [inline] kvmalloc_node+0x61/0x120 mm/util.c:587 kvmalloc include/linux/slab.h:741 [inline] kvzalloc include/linux/slab.h:749 [inline] alloc_netdev_mqs+0x98/0xec0 net/core/dev.c:10828 sixpack_open+0xfa/0xa50 drivers/net/hamradio/6pack.c:558 tty_ldisc_open+0x9b/0x110 drivers/tty/tty_ldisc.c:449 tty_set_ldisc+0x2f1/0x680 drivers/tty/tty_ldisc.c:579 tiocsetd drivers/tty/tty_io.c:2455 [inline] tty_ioctl+0xae0/0x1670 drivers/tty/tty_io.c:2741 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 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+0x44/0xae Freed by task 27306: kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free mm/kasan/common.c:328 [inline] __kasan_slab_free+0xff/0x130 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:1723 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1749 slab_free mm/slub.c:3513 [inline] kfree+0xf6/0x560 mm/slub.c:4561 kvfree+0x42/0x50 mm/util.c:620 device_release+0x9f/0x240 drivers/base/core.c:2230 kobject_cleanup lib/kobject.c:705 [inline] kobject_release lib/kobject.c:736 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1c8/0x540 lib/kobject.c:753 netdev_run_todo+0x75a/0xa80 net/core/dev.c:10638 sixpack_close+0x184/0x270 drivers/net/hamradio/6pack.c:675 tty_ldisc_close+0x110/0x190 drivers/tty/tty_ldisc.c:474 tty_ldisc_kill+0x94/0x150 drivers/tty/tty_ldisc.c:629 tty_ldisc_release+0x154/0x2a0 drivers/tty/tty_ldisc.c:803 tty_release_struct+0x20/0xe0 drivers/tty/tty_io.c:1706 tty_release+0xc70/0x1200 drivers/tty/tty_io.c:1878 __fput+0x286/0x9f0 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:175 [inline] exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff8880296bc000 which belongs to the cache kmalloc-cg-4k of size 4096 The buggy address is located 3216 bytes inside of 4096-byte region [ffff8880296bc000, ffff8880296bd000) The buggy address belongs to the page: page:ffffea0000a5ae00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x296b8 head:ffffea0000a5ae00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000001 ffff888010c4c280 raw: 0000000000000000 0000000000040004 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 11891, ts 539164162846, free_ts 471335544336 prep_new_page mm/page_alloc.c:2418 [inline] get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4149 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5369 alloc_pages+0x1a7/0x300 mm/mempolicy.c:2191 alloc_slab_page mm/slub.c:1793 [inline] allocate_slab mm/slub.c:1930 [inline] new_slab+0x32d/0x4a0 mm/slub.c:1993 ___slab_alloc+0x918/0xfe0 mm/slub.c:3022 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3109 slab_alloc_node mm/slub.c:3200 [inline] __kmalloc_node+0x2cb/0x390 mm/slub.c:4467 kmalloc_node include/linux/slab.h:613 [inline] kvmalloc_node+0x61/0x120 mm/util.c:587 kvmalloc include/linux/slab.h:741 [inline] seq_buf_alloc fs/seq_file.c:38 [inline] seq_read_iter+0x7e7/0x1240 fs/seq_file.c:210 kernfs_fop_read_iter+0x44f/0x5f0 fs/kernfs/file.c:241 call_read_iter include/linux/fs.h:2156 [inline] new_sync_read+0x421/0x6e0 fs/read_write.c:400 vfs_read+0x35c/0x600 fs/read_write.c:481 ksys_read+0x12d/0x250 fs/read_write.c:619 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+0x44/0xae page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1338 [inline] free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1389 free_unref_page_prepare mm/page_alloc.c:3309 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3388 __vunmap+0x781/0xb70 mm/vmalloc.c:2632 __vfree+0x3c/0xd0 mm/vmalloc.c:2680 vfree+0x5a/0x90 mm/vmalloc.c:2711 kcov_put kernel/kcov.c:411 [inline] kcov_put+0x26/0x40 kernel/kcov.c:407 kcov_close+0xc/0x10 kernel/kcov.c:513 __fput+0x286/0x9f0 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0xc14/0x2b40 kernel/exit.c:832 do_group_exit+0x125/0x310 kernel/exit.c:929 __do_sys_exit_group kernel/exit.c:940 [inline] __se_sys_exit_group kernel/exit.c:938 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:938 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+0x44/0xae Memory state around the buggy address: ffff8880296bcb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880296bcc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880296bcc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880296bcd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880296bcd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================