================================================================== BUG: KASAN: slab-out-of-bounds in instrument_atomic_read_write include/linux/instrumented.h:112 [inline] BUG: KASAN: slab-out-of-bounds in atomic_inc_not_zero include/linux/atomic/atomic-instrumented.h:1536 [inline] BUG: KASAN: slab-out-of-bounds in try_module_get+0x4c/0xd0 kernel/module/main.c:941 Write of size 4 at addr ffff88802cc6dd08 by task syz.8.4066/21400 CPU: 0 UID: 0 PID: 21400 Comm: syz.8.4066 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x13d/0x4b0 mm/kasan/report.c:482 kasan_report+0xdf/0x1d0 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:186 [inline] kasan_check_range+0x10f/0x1e0 mm/kasan/generic.c:200 instrument_atomic_read_write include/linux/instrumented.h:112 [inline] atomic_inc_not_zero include/linux/atomic/atomic-instrumented.h:1536 [inline] try_module_get+0x4c/0xd0 kernel/module/main.c:941 dvb_device_open+0x124/0x3b0 drivers/media/dvb-core/dvbdev.c:103 chrdev_open+0x234/0x6a0 fs/char_dev.c:411 do_dentry_open+0x6d8/0x1660 fs/open.c:947 vfs_open+0x82/0x3f0 fs/open.c:1079 do_open fs/namei.c:4699 [inline] path_openat+0x208c/0x31a0 fs/namei.c:4858 do_file_open+0x20e/0x430 fs/namei.c:4887 do_sys_openat2+0x10d/0x1e0 fs/open.c:1364 do_sys_open fs/open.c:1370 [inline] __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __x64_sys_openat+0x12d/0x210 fs/open.c:1381 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f820a15d68e Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08 RSP: 002b:00007f820b104b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f820b1056c0 RCX: 00007f820a15d68e RDX: 0000000000000002 RSI: 00007f820b104c00 RDI: ffffffffffffff9c RBP: 00007f820b104c00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd R13: 00007f820a416038 R14: 00007f820a415fa0 R15: 00007ffc906dc598 Allocated by task 20564: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kmalloc_noprof include/linux/slab.h:950 [inline] tc_action_net_init include/net/act_api.h:163 [inline] police_init_net+0x56/0x270 net/sched/act_police.c:509 ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137 setup_net+0x118/0x3a0 net/core/net_namespace.c:446 copy_net_ns+0x46f/0x7c0 net/core/net_namespace.c:579 create_new_namespaces+0x3ea/0xac0 kernel/nsproxy.c:132 unshare_nsproxy_namespaces+0xf2/0x220 kernel/nsproxy.c:234 ksys_unshare+0x438/0xab0 kernel/fork.c:3243 __do_sys_unshare kernel/fork.c:3317 [inline] __se_sys_unshare kernel/fork.c:3315 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3315 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88802cc6dc00 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 32 bytes to the right of allocated 232-byte region [ffff88802cc6dc00, ffff88802cc6dce8) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2cc6c head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801b842b40 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b842b40 dead000000000100 dead000000000122 head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 00fff00000000001 ffffffffffffff81 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 36, tgid 36 (kdevtmpfs), ts 17367760619, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1858 prep_new_page mm/page_alloc.c:1866 [inline] get_page_from_freelist+0x11a6/0x33b0 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x27c/0x2bc0 mm/page_alloc.c:5226 alloc_slab_page mm/slub.c:3278 [inline] allocate_slab mm/slub.c:3467 [inline] new_slab+0xa6/0x6c0 mm/slub.c:3525 refill_objects+0x277/0x420 mm/slub.c:7271 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x375/0x650 mm/slub.c:4651 alloc_from_pcs mm/slub.c:4749 [inline] slab_alloc_node mm/slub.c:4883 [inline] __do_kmalloc_node mm/slub.c:5294 [inline] __kmalloc_noprof+0x688/0x850 mm/slub.c:5307 kmalloc_noprof include/linux/slab.h:954 [inline] kmalloc_array_noprof include/linux/slab.h:1097 [inline] security_inode_init_security+0x113/0x370 security/security.c:1347 shmem_mknod+0x2ce/0x480 mm/shmem.c:3868 vfs_mknod+0x3a5/0x7f0 fs/namei.c:5120 handle_create drivers/base/devtmpfs.c:232 [inline] handle drivers/base/devtmpfs.c:384 [inline] devtmpfs_work_loop+0x48d/0xae4 drivers/base/devtmpfs.c:399 devtmpfsd+0x3f/0x50 drivers/base/devtmpfs.c:441 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 page_owner free stack trace missing Memory state around the buggy address: ffff88802cc6dc00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88802cc6dc80: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc >ffff88802cc6dd00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88802cc6dd80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88802cc6de00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================