On Tue, 6 Sept 2022 at 09:36, syzbot <syzbot+9228d6098455bb209ec8@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following issue on: > > HEAD commit: c5e4d5e99162 Merge tag 'fscache-fixes-20220831' of git://g.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=142e0e1b080000 > kernel config: https://syzkaller.appspot.com/x/.config?x=9c5c41fc03fda66f > dashboard link: https://syzkaller.appspot.com/bug?extid=9228d6098455bb209ec8 > compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2 > > Unfortunately, I don't have any reproducer for this issue yet. > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+9228d6098455bb209ec8@xxxxxxxxxxxxxxxxxxxxxxxxx Looks like the issue is in dma-buf.c +dma-buf.c maintainers > ================================================================== > BUG: KASAN: use-after-free in task_work_run+0x126/0x1c0 kernel/task_work.c:176 > Read of size 8 at addr ffff88801d1fe500 by task syz-executor.2/18582 > > CPU: 0 PID: 18582 Comm: syz-executor.2 Not tainted 6.0.0-rc3-syzkaller-00031-gc5e4d5e99162 #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 > Call Trace: > <TASK> > __dump_stack lib/dump_stack.c:88 [inline] > dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 > print_address_description+0x65/0x4b0 mm/kasan/report.c:317 > print_report+0x108/0x220 mm/kasan/report.c:433 > kasan_report+0xfb/0x130 mm/kasan/report.c:495 > task_work_run+0x126/0x1c0 kernel/task_work.c:176 > resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] > exit_to_user_mode_loop+0x134/0x160 kernel/entry/common.c:169 > exit_to_user_mode_prepare+0xad/0x110 kernel/entry/common.c:201 > __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] > syscall_exit_to_user_mode+0x2e/0x60 kernel/entry/common.c:294 > entry_SYSCALL_64_after_hwframe+0x63/0xcd > RIP: 0033:0x7f287f289279 > 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:00007f28804cd168 EFLAGS: 00000246 ORIG_RAX: 0000000000000119 > RAX: 0000000000000001 RBX: 00007f287f39bf80 RCX: 00007f287f289279 > RDX: 0000000000000001 RSI: 0000000020000000 RDI: 0000000000000003 > RBP: 00007f287f2e32e9 R08: 0000000000000000 R09: 0000000000000000 > R10: 00000000000006ff R11: 0000000000000246 R12: 0000000000000000 > R13: 00007ffd34f4ba0f R14: 00007f28804cd300 R15: 0000000000022000 > </TASK> > > Allocated by task 18586: > kasan_save_stack mm/kasan/common.c:38 [inline] > kasan_set_track mm/kasan/common.c:45 [inline] > set_alloc_info mm/kasan/common.c:437 [inline] > __kasan_slab_alloc+0xb2/0xe0 mm/kasan/common.c:470 > kasan_slab_alloc include/linux/kasan.h:224 [inline] > slab_post_alloc_hook mm/slab.h:727 [inline] > slab_alloc_node mm/slub.c:3243 [inline] > slab_alloc mm/slub.c:3251 [inline] > __kmem_cache_alloc_lru mm/slub.c:3258 [inline] > kmem_cache_alloc+0x1a6/0x310 mm/slub.c:3268 > kmem_cache_zalloc include/linux/slab.h:723 [inline] > __alloc_file+0x26/0x230 fs/file_table.c:138 > alloc_empty_file+0xa9/0x1b0 fs/file_table.c:187 > alloc_file+0x58/0x5e0 fs/file_table.c:229 > alloc_file_pseudo+0x260/0x300 fs/file_table.c:272 > dma_buf_getfile drivers/dma-buf/dma-buf.c:534 [inline] > dma_buf_export+0x634/0x920 drivers/dma-buf/dma-buf.c:652 > drm_gem_dmabuf_export drivers/gpu/drm/drm_prime.c:253 [inline] > drm_gem_prime_export+0x255/0x400 drivers/gpu/drm/drm_prime.c:895 > export_and_register_object drivers/gpu/drm/drm_prime.c:397 [inline] > drm_gem_prime_handle_to_fd+0x3e6/0x530 drivers/gpu/drm/drm_prime.c:465 > drm_ioctl_kernel+0x33e/0x4f0 drivers/gpu/drm/drm_ioctl.c:782 > drm_ioctl+0x626/0xa10 drivers/gpu/drm/drm_ioctl.c:885 > vfs_ioctl fs/ioctl.c:51 [inline] > __do_sys_ioctl fs/ioctl.c:870 [inline] > __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:856 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x63/0xcd > > Freed by task 18595: > kasan_save_stack mm/kasan/common.c:38 [inline] > kasan_set_track+0x4c/0x70 mm/kasan/common.c:45 > kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:370 > ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:367 > kasan_slab_free include/linux/kasan.h:200 [inline] > slab_free_hook mm/slub.c:1754 [inline] > slab_free_freelist_hook+0x12e/0x1a0 mm/slub.c:1780 > slab_free mm/slub.c:3534 [inline] > kmem_cache_free+0x95/0x1d0 mm/slub.c:3551 > rcu_do_batch kernel/rcu/tree.c:2245 [inline] > rcu_core+0xa61/0x1710 kernel/rcu/tree.c:2505 > __do_softirq+0x382/0x793 kernel/softirq.c:571 > > Last potentially related work creation: > kasan_save_stack+0x3b/0x60 mm/kasan/common.c:38 > __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:348 > call_rcu+0x163/0x9c0 kernel/rcu/tree.c:2793 > task_work_run+0x146/0x1c0 kernel/task_work.c:177 > resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] > exit_to_user_mode_loop+0x134/0x160 kernel/entry/common.c:169 > exit_to_user_mode_prepare+0xad/0x110 kernel/entry/common.c:201 > __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] > syscall_exit_to_user_mode+0x2e/0x60 kernel/entry/common.c:294 > entry_SYSCALL_64_after_hwframe+0x63/0xcd > > Second to last potentially related work creation: > kasan_save_stack+0x3b/0x60 mm/kasan/common.c:38 > __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:348 > task_work_add+0x2f/0x200 kernel/task_work.c:48 > fput+0xdc/0x1a0 fs/file_table.c:381 > dma_buf_poll_cb drivers/dma-buf/dma-buf.c:213 [inline] > dma_buf_poll+0x53a/0x680 drivers/dma-buf/dma-buf.c:295 > vfs_poll include/linux/poll.h:88 [inline] > ep_item_poll fs/eventpoll.c:853 [inline] > ep_send_events fs/eventpoll.c:1692 [inline] > ep_poll+0xb27/0x1e60 fs/eventpoll.c:1821 > do_epoll_wait+0x1a2/0x210 fs/eventpoll.c:2256 > do_epoll_pwait fs/eventpoll.c:2290 [inline] > __do_sys_epoll_pwait fs/eventpoll.c:2303 [inline] > __se_sys_epoll_pwait+0x28e/0x480 fs/eventpoll.c:2297 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x63/0xcd > > The buggy address belongs to the object at ffff88801d1fe500 > which belongs to the cache filp of size 456 > The buggy address is located 0 bytes inside of > 456-byte region [ffff88801d1fe500, ffff88801d1fe6c8) > > The buggy address belongs to the physical page: > page:ffffea0000747f80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1d1fe > head:ffffea0000747f80 order:1 compound_mapcount:0 compound_pincount:0 > memcg:ffff888072449c01 > flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) > raw: 00fff00000010200 ffffea00005ddf80 dead000000000002 ffff888140007a00 > raw: 0000000000000000 00000000000c000c 00000001ffffffff ffff888072449c01 > page dumped because: kasan: bad access detected > page_owner tracks the page as allocated > page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3111, tgid 3111 (v4l_id), ts 20130623440, free_ts 19733718234 > prep_new_page mm/page_alloc.c:2532 [inline] > get_page_from_freelist+0x72b/0x7a0 mm/page_alloc.c:4283 > __alloc_pages+0x259/0x560 mm/page_alloc.c:5515 > alloc_slab_page+0x70/0xf0 mm/slub.c:1824 > allocate_slab+0x5e/0x520 mm/slub.c:1969 > new_slab mm/slub.c:2029 [inline] > ___slab_alloc+0x42e/0xce0 mm/slub.c:3031 > __slab_alloc mm/slub.c:3118 [inline] > slab_alloc_node mm/slub.c:3209 [inline] > slab_alloc mm/slub.c:3251 [inline] > __kmem_cache_alloc_lru mm/slub.c:3258 [inline] > kmem_cache_alloc+0x25d/0x310 mm/slub.c:3268 > kmem_cache_zalloc include/linux/slab.h:723 [inline] > __alloc_file+0x26/0x230 fs/file_table.c:138 > alloc_empty_file+0xa9/0x1b0 fs/file_table.c:187 > path_openat+0xf1/0x2e00 fs/namei.c:3677 > do_filp_open+0x275/0x500 fs/namei.c:3718 > do_sys_openat2+0x13b/0x500 fs/open.c:1311 > do_sys_open fs/open.c:1327 [inline] > __do_sys_openat fs/open.c:1343 [inline] > __se_sys_openat fs/open.c:1338 [inline] > __x64_sys_openat+0x243/0x290 fs/open.c:1338 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x2b/0x70 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:1449 [inline] > free_pcp_prepare+0x812/0x900 mm/page_alloc.c:1499 > free_unref_page_prepare mm/page_alloc.c:3380 [inline] > free_unref_page+0x7d/0x630 mm/page_alloc.c:3476 > qlist_free_all+0x2b/0x70 mm/kasan/quarantine.c:187 > kasan_quarantine_reduce+0x169/0x180 mm/kasan/quarantine.c:294 > __kasan_slab_alloc+0x2f/0xe0 mm/kasan/common.c:447 > kasan_slab_alloc include/linux/kasan.h:224 [inline] > slab_post_alloc_hook mm/slab.h:727 [inline] > slab_alloc_node mm/slub.c:3243 [inline] > slab_alloc mm/slub.c:3251 [inline] > __kmem_cache_alloc_lru mm/slub.c:3258 [inline] > kmem_cache_alloc+0x1a6/0x310 mm/slub.c:3268 > vm_area_alloc+0x20/0xe0 kernel/fork.c:459 > mmap_region+0xb4a/0x16f0 mm/mmap.c:1732 > do_mmap+0x7a7/0xdf0 mm/mmap.c:1540 > vm_mmap_pgoff+0x1e5/0x2f0 mm/util.c:552 > ksys_mmap_pgoff+0x48c/0x6d0 mm/mmap.c:1586 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x63/0xcd > > Memory state around the buggy address: > ffff88801d1fe400: fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc > ffff88801d1fe480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > >ffff88801d1fe500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ^ > ffff88801d1fe580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff88801d1fe600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ================================================================== > > > --- > This report is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@xxxxxxxxxxxxxxxx. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/000000000000fad77705e7fd40fb%40google.com.
