syzbot

 sign-in | mailing list | source | docs
🐞 Open [1576]
≡ Subsystems
🐞 Fixed [6322]
🐞 Invalid [16105]
⬇ Missing Backports [191]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
Total Repo Heatmap Subsystems Heatmap
💬 Send us feedback

KASAN: use-after-free Read in handle_tx (2)

Status: auto-obsoleted due to no activity on 2023/05/11 18:22
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+2bbd110ed387521bdf86@syzkaller.appspotmail.com
First crash: 864d, last: 864d
▶ ▼ Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: use-after-free Read in handle_tx net 15 1228d 1341d 0/29 auto-closed as invalid on 2022/05/12 13:20
linux-6.1 KASAN: use-after-free Read in handle_tx 1 239d 239d 0/3 auto-obsoleted due to no activity on 2025/02/05 09:49
linux-6.1 KASAN: use-after-free Read in handle_tx (2) 3 91d 113d 0/3 upstream: reported on 2025/03/02 20:36
upstream KASAN: slab-use-after-free Read in handle_tx (2) net C 421 1h01m 488d 0/29 upstream: reported C repro on 2024/02/21 10:58
upstream KASAN: slab-use-after-free Read in handle_tx net 1 695d 691d 0/29 auto-obsoleted due to no activity on 2023/10/27 13:43

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in handle_tx+0x573/0x610 drivers/net/caif/caif_serial.c:236
Read of size 8 at addr ffff888076ab5018 by task aoe_tx0/1201

CPU: 1 PID: 1201 Comm: aoe_tx0 Not tainted 6.2.0-rc7-syzkaller-00135-g38c1e0c65865 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:306 [inline]
 print_report+0x15e/0x45d mm/kasan/report.c:417
 kasan_report+0xbf/0x1f0 mm/kasan/report.c:517
 handle_tx+0x573/0x610 drivers/net/caif/caif_serial.c:236
 __netdev_start_xmit include/linux/netdevice.h:4865 [inline]
 netdev_start_xmit include/linux/netdevice.h:4879 [inline]
 xmit_one net/core/dev.c:3583 [inline]
 dev_hard_start_xmit+0x1c2/0x990 net/core/dev.c:3599
 __dev_queue_xmit+0x2cdf/0x3ba0 net/core/dev.c:4249
 dev_queue_xmit include/linux/netdevice.h:3035 [inline]
 tx+0x6e/0xc0 drivers/block/aoe/aoenet.c:63
 kthread+0x1eb/0x3b0 drivers/block/aoe/aoecmd.c:1229
 kthread+0x2e8/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>

Allocated by task 5855:
 kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 ____kasan_kmalloc mm/kasan/common.c:371 [inline]
 ____kasan_kmalloc mm/kasan/common.c:330 [inline]
 __kasan_kmalloc+0xa5/0xb0 mm/kasan/common.c:380
 kmalloc include/linux/slab.h:580 [inline]
 kzalloc include/linux/slab.h:720 [inline]
 alloc_tty_struct+0x98/0x8e0 drivers/tty/tty_io.c:3088
 tty_init_dev.part.0+0x20/0x5d0 drivers/tty/tty_io.c:1406
 tty_init_dev include/linux/err.h:36 [inline]
 tty_open_by_driver drivers/tty/tty_io.c:2079 [inline]
 tty_open+0xacc/0xfb0 drivers/tty/tty_io.c:2126
 chrdev_open+0x26a/0x770 fs/char_dev.c:414
 do_dentry_open+0x6cc/0x13f0 fs/open.c:882
 do_open fs/namei.c:3557 [inline]
 path_openat+0x1bbc/0x2a50 fs/namei.c:3714
 do_filp_open+0x1ba/0x410 fs/namei.c:3741
 do_sys_openat2+0x16d/0x4c0 fs/open.c:1310
 do_sys_open fs/open.c:1326 [inline]
 __do_sys_openat fs/open.c:1342 [inline]
 __se_sys_openat fs/open.c:1337 [inline]
 __x64_sys_openat+0x143/0x1f0 fs/open.c:1337
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Freed by task 5155:
 kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:518
 ____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:1781 [inline]
 slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1807
 slab_free mm/slub.c:3787 [inline]
 __kmem_cache_free+0xaf/0x3b0 mm/slub.c:3800
 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289
 worker_thread+0x669/0x1090 kernel/workqueue.c:2436
 kthread+0x2e8/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

Last potentially related work creation:
 kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:488
 insert_work+0x48/0x350 kernel/workqueue.c:1358
 __queue_work+0x693/0x13b0 kernel/workqueue.c:1517
 queue_work_on+0xf2/0x110 kernel/workqueue.c:1545
 kref_put include/linux/kref.h:65 [inline]
 tty_kref_put drivers/tty/tty_io.c:1563 [inline]
 release_tty+0x4d9/0x600 drivers/tty/tty_io.c:1599
 tty_release_struct+0xb8/0xf0 drivers/tty/tty_io.c:1698
 tty_release+0xc14/0x11b0 drivers/tty/tty_io.c:1858
 __fput+0x27c/0xa90 fs/file_table.c:320
 task_work_run+0x16f/0x270 kernel/task_work.c:179
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xaa8/0x2950 kernel/exit.c:867
 do_group_exit+0xd4/0x2a0 kernel/exit.c:1012
 get_signal+0x21c3/0x2450 kernel/signal.c:2859
 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306
 exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
 exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:203
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296
 ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:301

Second to last potentially related work creation:
 kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:488
 __call_rcu_common.constprop.0+0x99/0x820 kernel/rcu/tree.c:2755
 in6_dev_finish_destroy+0x172/0x1f0 net/ipv6/addrconf_core.c:271
 in6_dev_put include/net/addrconf.h:380 [inline]
 in6_dev_put_clear include/net/addrconf.h:388 [inline]
 ip6_route_dev_notify+0x60c/0x7a0 net/ipv6/route.c:6299
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:87
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1944
 call_netdevice_notifiers_extack net/core/dev.c:1982 [inline]
 call_netdevice_notifiers net/core/dev.c:1996 [inline]
 unregister_netdevice_many_notify+0xa2b/0x19e0 net/core/dev.c:10839
 unregister_netdevice_many net/core/dev.c:10895 [inline]
 default_device_exit_batch+0x451/0x590 net/core/dev.c:11348
 ops_exit_list+0x125/0x170 net/core/net_namespace.c:174
 setup_net+0x9bd/0xe60 net/core/net_namespace.c:356
 copy_net_ns+0x31b/0x6b0 net/core/net_namespace.c:483
 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110
 copy_namespaces+0x3b3/0x4a0 kernel/nsproxy.c:179
 copy_process+0x30d3/0x7520 kernel/fork.c:2269
 kernel_clone+0xeb/0x990 kernel/fork.c:2681
 __do_sys_clone+0xba/0x100 kernel/fork.c:2822
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

The buggy address belongs to the object at ffff888076ab5000
 which belongs to the cache kmalloc-cg-2k of size 2048
The buggy address is located 24 bytes inside of
 2048-byte region [ffff888076ab5000, ffff888076ab5800)

The buggy address belongs to the physical page:
page:ffffea0001daac00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x76ab0
head:ffffea0001daac00 order:3 compound_mapcount:0 subpages_mapcount:0 compound_pincount:0
memcg:ffff88802143fe01
anon flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffff88801244f3c0 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000080008 00000001ffffffff ffff88802143fe01
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5623, tgid 5613 (syz-executor.3), ts 209505202279, free_ts 209488411666
 prep_new_page mm/page_alloc.c:2531 [inline]
 get_page_from_freelist+0x119c/0x2ce0 mm/page_alloc.c:4283
 __alloc_pages+0x1cb/0x5b0 mm/page_alloc.c:5549
 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2287
 alloc_slab_page mm/slub.c:1851 [inline]
 allocate_slab+0x25f/0x350 mm/slub.c:1998
 new_slab mm/slub.c:2051 [inline]
 ___slab_alloc+0xa91/0x1400 mm/slub.c:3193
 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3292
 __slab_alloc_node mm/slub.c:3345 [inline]
 slab_alloc_node mm/slub.c:3442 [inline]
 __kmem_cache_alloc_node+0x1a4/0x430 mm/slub.c:3491
 __do_kmalloc_node mm/slab_common.c:967 [inline]
 __kmalloc+0x4a/0xd0 mm/slab_common.c:981
 kmalloc include/linux/slab.h:584 [inline]
 kzalloc include/linux/slab.h:720 [inline]
 __register_sysctl_table+0x116/0x10a0 fs/proc/proc_sysctl.c:1337
 __addrconf_sysctl_register+0x1db/0x3d0 net/ipv6/addrconf.c:7088
 addrconf_init_net+0x51f/0x900 net/ipv6/addrconf.c:7207
 ops_init+0xb9/0x670 net/core/net_namespace.c:135
 setup_net+0x793/0xe60 net/core/net_namespace.c:333
 copy_net_ns+0x31b/0x6b0 net/core/net_namespace.c:483
 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110
 copy_namespaces+0x3b3/0x4a0 kernel/nsproxy.c:179
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1446 [inline]
 free_pcp_prepare+0x65c/0xc00 mm/page_alloc.c:1496
 free_unref_page_prepare mm/page_alloc.c:3369 [inline]
 free_unref_page+0x1d/0x490 mm/page_alloc.c:3464
 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2637
 qlink_free mm/kasan/quarantine.c:168 [inline]
 qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187
 kasan_quarantine_reduce+0x192/0x220 mm/kasan/quarantine.c:294
 __kasan_slab_alloc+0x66/0x90 mm/kasan/common.c:302
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slab.h:761 [inline]
 slab_alloc_node mm/slub.c:3452 [inline]
 slab_alloc mm/slub.c:3460 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3467 [inline]
 kmem_cache_alloc_lru+0x26d/0x760 mm/slub.c:3483
 __d_alloc+0x32/0x980 fs/dcache.c:1769
 d_alloc+0x4e/0x240 fs/dcache.c:1849
 d_alloc_parallel+0xe8/0x1410 fs/dcache.c:2638
 __lookup_slow+0x193/0x460 fs/namei.c:1670
 lookup_slow fs/namei.c:1702 [inline]
 walk_component+0x33f/0x5a0 fs/namei.c:1993
 lookup_last fs/namei.c:2450 [inline]
 path_lookupat+0x1ba/0x840 fs/namei.c:2474
 filename_lookup+0x1d2/0x590 fs/namei.c:2503
 vfs_statx+0x14c/0x430 fs/stat.c:232
 vfs_fstatat+0x90/0xb0 fs/stat.c:270

Memory state around the buggy address:
 ffff888076ab4f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888076ab4f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888076ab5000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888076ab5080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888076ab5100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/02/10 18:22 upstream 38c1e0c65865 95871dcc .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root KASAN: use-after-free Read in handle_tx
* Struck through repros no longer work on HEAD.