================================================================== BUG: KFENCE: use-after-free read in dvb_device_open+0xee/0x3b0 drivers/media/dvb-core/dvbdev.c:99 Use-after-free read at 0xffff88816db5a018 (in kfence-#172): dvb_device_open+0xee/0x3b0 drivers/media/dvb-core/dvbdev.c:99 chrdev_open+0x234/0x6a0 fs/char_dev.c:411 do_dentry_open+0x6d8/0x1660 fs/open.c:949 vfs_open+0x82/0x3f0 fs/open.c:1081 do_open fs/namei.c:4671 [inline] path_openat+0x208c/0x31a0 fs/namei.c:4830 do_file_open+0x20e/0x430 fs/namei.c:4859 do_sys_openat2+0x10d/0x1e0 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x12d/0x210 fs/open.c:1383 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f kfence-#172: 0xffff88816db5a000-0xffff88816db5a03b, size=60, cache=kmalloc-64 allocated by task 5931 on cpu 3 at 235.815979s (2.886787s ago): kmalloc_noprof include/linux/slab.h:962 [inline] kzalloc_noprof include/linux/slab.h:1200 [inline] tomoyo_encode2+0xfb/0x3c0 security/tomoyo/realpath.c:45 tomoyo_encode+0x29/0x50 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x18c/0x690 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x276/0x460 security/tomoyo/file.c:827 security_inode_getattr+0x116/0x280 security/security.c:1869 vfs_getattr fs/stat.c:259 [inline] vfs_fstat+0x4b/0xe0 fs/stat.c:281 __do_sys_newfstat+0x8b/0x110 fs/stat.c:551 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f freed by task 5931 on cpu 3 at 235.816034s (2.903975s ago): tomoyo_path_perm+0x29c/0x460 security/tomoyo/file.c:847 security_inode_getattr+0x116/0x280 security/security.c:1869 vfs_getattr fs/stat.c:259 [inline] vfs_fstat+0x4b/0xe0 fs/stat.c:281 __do_sys_newfstat+0x8b/0x110 fs/stat.c:551 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f CPU: 2 UID: 0 PID: 12653 Comm: syz.6.2298 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 RIP: 0010:dvb_device_open+0xee/0x3b0 drivers/media/dvb-core/dvbdev.c:99 Code: 0f 84 3f 02 00 00 e8 d1 b4 28 fa 48 8d 7d 18 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 4c 02 00 00 <4c> 8b 6d 18 4d 85 ed 0f 84 0e 02 00 00 e8 a0 b4 28 fa 4c 89 ea 48 RSP: 0018:ffffc90005f478d0 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc9002ced7000 RDX: 1ffff1102db6b403 RSI: ffffffff87de804f RDI: ffff88816db5a018 RBP: ffff88816db5a000 R08: 0000000000000001 R09: fffffbfff1fd7995 R10: ffffffff8febccaf R11: 0000000000000000 R12: ffff88805814ba40 R13: ffffffff87de7f80 R14: ffff88802579e288 R15: ffff88805814ba88 FS: 00007f8696e926c0(0000) GS:ffff8880d65a8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff88816db5a018 CR3: 00000000398ec000 CR4: 0000000000352ef0 Call Trace: chrdev_open+0x234/0x6a0 fs/char_dev.c:411 do_dentry_open+0x6d8/0x1660 fs/open.c:949 vfs_open+0x82/0x3f0 fs/open.c:1081 do_open fs/namei.c:4671 [inline] path_openat+0x208c/0x31a0 fs/namei.c:4830 do_file_open+0x20e/0x430 fs/namei.c:4859 do_sys_openat2+0x10d/0x1e0 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x12d/0x210 fs/open.c:1383 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8695f5c84e 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:00007f8696e91b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f8696e926c0 RCX: 00007f8695f5c84e RDX: 0000000000000002 RSI: 00007f8696e91c00 RDI: ffffffffffffff9c RBP: 00007f8696e91c00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd R13: 00007f8696216038 R14: 00007f8696215fa0 R15: 00007ffca0d88028 ================================================================== ---------------- Code disassembly (best guess): 0: 0f 84 3f 02 00 00 je 0x245 6: e8 d1 b4 28 fa call 0xfa28b4dc b: 48 8d 7d 18 lea 0x18(%rbp),%rdi f: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 16: fc ff df 19: 48 89 fa mov %rdi,%rdx 1c: 48 c1 ea 03 shr $0x3,%rdx 20: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 24: 0f 85 4c 02 00 00 jne 0x276 * 2a: 4c 8b 6d 18 mov 0x18(%rbp),%r13 <-- trapping instruction 2e: 4d 85 ed test %r13,%r13 31: 0f 84 0e 02 00 00 je 0x245 37: e8 a0 b4 28 fa call 0xfa28b4dc 3c: 4c 89 ea mov %r13,%rdx 3f: 48 rex.W