KASAN: null-ptr-deref Read in drm_dp_aux_dev_get_by


Created	Duration	User	Repo	Result
2020/09/06 11:03	3h40m	bisect fix	linux-4.19.y	OK (1) job log
2020/08/07 08:39	26m	bisect fix	linux-4.19.y	OK (0) job log log
2020/07/08 08:15	24m	bisect fix	linux-4.19.y	OK (0) job log log

MINIX-fs: mounting unchecked file system, running fsck is recommended audit: type=1800 audit(1591600222.446:9): pid=6445 uid=0 auid=0 ses=5 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="syz-executor477" name="file0" dev="sda1" ino=15703 res=0 ================================================================== BUG: KASAN: null-ptr-deref in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] BUG: KASAN: null-ptr-deref in refcount_add_not_zero arch/x86/include/asm/refcount.h:85 [inline] BUG: KASAN: null-ptr-deref in refcount_inc_not_zero arch/x86/include/asm/refcount.h:107 [inline] BUG: KASAN: null-ptr-deref in kref_get_unless_zero include/linux/kref.h:116 [inline] BUG: KASAN: null-ptr-deref in drm_dp_aux_dev_get_by_minor+0x92/0x1f0 drivers/gpu/drm/drm_dp_aux_dev.c:63 Read of size 4 at addr 0000000000000018 by task syz-executor477/6445 CPU: 0 PID: 6445 Comm: syz-executor477 Not tainted 4.19.127-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2fe lib/dump_stack.c:118 kasan_report_error mm/kasan/report.c:352 [inline] kasan_report mm/kasan/report.c:412 [inline] kasan_report.cold+0x194/0x2b9 mm/kasan/report.c:396 atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] refcount_add_not_zero arch/x86/include/asm/refcount.h:85 [inline] refcount_inc_not_zero arch/x86/include/asm/refcount.h:107 [inline] kref_get_unless_zero include/linux/kref.h:116 [inline] drm_dp_aux_dev_get_by_minor+0x92/0x1f0 drivers/gpu/drm/drm_dp_aux_dev.c:63 auxdev_open+0x47/0xa0 drivers/gpu/drm/drm_dp_aux_dev.c:131 chrdev_open+0x219/0x5c0 fs/char_dev.c:423 do_dentry_open+0x4a8/0x1160 fs/open.c:796 do_last fs/namei.c:3421 [inline] path_openat+0xe06/0x2eb0 fs/namei.c:3537 do_filp_open+0x1a1/0x280 fs/namei.c:3567 file_open_name+0x291/0x370 fs/open.c:1032 acct_on kernel/acct.c:207 [inline] __do_sys_acct kernel/acct.c:286 [inline] __se_sys_acct+0xf2/0x930 kernel/acct.c:273 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x444ac9 Code: 0d d8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 db d7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffd7380f348 EFLAGS: 00000246 ORIG_RAX: 00000000000000a3 RAX: ffffffffffffffda RBX: 00007ffd7380f350 RCX: 0000000000444ac9 RDX: 0000000000401470 RSI: 44eadf382f7582d4 RDI: 0000000020000480 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000400eb0 R10: 00007ffd7380f220 R11: 0000000000000246 R12: 0000000000402730 R13: 00000000004027c0 R14: 0000000000000000 R15: 0000000000000000 ==================================================================