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KMSAN: kernel-infoleak in vcs_read (2)
Status: upstream: reported C repro on 2019/12/04 15:25
Reported-by: syzbot+31a641689d43387f05d3@syzkaller.appspotmail.com
First crash: 903d, last: 9h35m
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KMSAN: kernel-infoleak in vcs_read C 531 1437d 1447d 9/22 fixed on 2018/07/13 11:20
upstream KMSAN: uninit-value in set_selection_kernel 386 14d 804d 0/22 upstream: reported on 2020/03/12 21:47
upstream KMSAN: kernel-infoleak in _copy_to_iter (7) C 161 6h56m 77d 21/22 internal: reported C repro on 2022/03/09 07:32
Patch testing requests:
Created Duration User Patch Repo Result
2021/03/31 15:50 32m phil@philpotter.co.uk https://github.com/google/kmsan.git master OK
2020/09/30 20:23 3m anant.thazhemadam@gmail.com patch https://github.com/google/kmsan.git master error
2020/09/30 18:10 18m anant.thazhemadam@gmail.com patch https://github.com/google/kmsan.git master report log
2020/09/30 01:00 3m anant.thazhemadam@gmail.com patch https://github.com/google/kmsan.git master error

Sample crash report:
=====================================================
BUG: KMSAN: kernel-infoleak in kmsan_copy_to_user+0x81/0x90 mm/kmsan/kmsan_hooks.c:253
CPU: 0 PID: 8471 Comm: syz-executor446 Not tainted 5.8.0-rc5-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+0x21c/0x280 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121
 kmsan_internal_check_memory+0x19d/0x3d0 mm/kmsan/kmsan.c:443
 kmsan_copy_to_user+0x81/0x90 mm/kmsan/kmsan_hooks.c:253
 instrument_copy_to_user include/linux/instrumented.h:91 [inline]
 _copy_to_user+0x18e/0x260 lib/usercopy.c:33
 copy_to_user include/linux/uaccess.h:170 [inline]
 vcs_read+0x1c6f/0x2920 drivers/tty/vt/vc_screen.c:424
 vfs_read+0x577/0x14d0 fs/read_write.c:479
 ksys_read+0x275/0x500 fs/read_write.c:607
 __do_sys_read fs/read_write.c:617 [inline]
 __se_sys_read+0x92/0xb0 fs/read_write.c:615
 __x64_sys_read+0x4a/0x70 fs/read_write.c:615
 do_syscall_64+0xad/0x160 arch/x86/entry/common.c:386
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4453c9
Code: Bad RIP value.
RSP: 002b:00007fffa3c8af98 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004453c9
RDX: 0000000000002020 RSI: 0000000020000100 RDI: 0000000000000003
RBP: 0000000000022239 R08: 00000000004002e0 R09: 00000000004002e0
R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000402590
R13: 0000000000402620 R14: 0000000000000000 R15: 0000000000000000

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
 kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:310
 kmsan_memcpy_memmove_metadata+0x272/0x2e0 mm/kmsan/kmsan.c:247
 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:267
 __msan_memcpy+0x43/0x50 mm/kmsan/kmsan_instr.c:116
 vc_uniscr_copy_line+0x545/0x800 drivers/tty/vt/vt.c:572
 vcs_read+0x107d/0x2920 drivers/tty/vt/vc_screen.c:332
 vfs_read+0x577/0x14d0 fs/read_write.c:479
 ksys_read+0x275/0x500 fs/read_write.c:607
 __do_sys_read fs/read_write.c:617 [inline]
 __se_sys_read+0x92/0xb0 fs/read_write.c:615
 __x64_sys_read+0x4a/0x70 fs/read_write.c:615
 do_syscall_64+0xad/0x160 arch/x86/entry/common.c:386
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Uninit was created at:
 kmsan_save_stack_with_flags+0x3c/0x90 mm/kmsan/kmsan.c:144
 kmsan_internal_alloc_meta_for_pages mm/kmsan/kmsan_shadow.c:269 [inline]
 kmsan_alloc_page+0xc5/0x1a0 mm/kmsan/kmsan_shadow.c:293
 __alloc_pages_nodemask+0xdf0/0x1030 mm/page_alloc.c:4889
 alloc_pages_current+0x685/0xb50 mm/mempolicy.c:2292
 alloc_pages include/linux/gfp.h:545 [inline]
 __vmalloc_area_node mm/vmalloc.c:2489 [inline]
 __vmalloc_node_range+0x989/0x1400 mm/vmalloc.c:2555
 __vmalloc_node mm/vmalloc.c:2598 [inline]
 vmalloc+0xe0/0xf0 mm/vmalloc.c:2631
 vc_uniscr_alloc drivers/tty/vt/vt.c:354 [inline]
 vc_do_resize+0x73e/0x38f0 drivers/tty/vt/vt.c:1222
 vc_resize+0xc3/0xe0 drivers/tty/vt/vt.c:1334
 fbcon_modechanged+0xdc1/0x1320 drivers/video/fbdev/core/fbcon.c:2990
 fbcon_update_vcs+0x86/0xa0 drivers/video/fbdev/core/fbcon.c:3048
 fb_set_var+0x1420/0x1850 drivers/video/fbdev/core/fbmem.c:1056
 do_fb_ioctl+0xc00/0x1150 drivers/video/fbdev/core/fbmem.c:1109
 fb_ioctl+0x1e4/0x210 drivers/video/fbdev/core/fbmem.c:1185
 vfs_ioctl fs/ioctl.c:48 [inline]
 ksys_ioctl fs/ioctl.c:753 [inline]
 __do_sys_ioctl fs/ioctl.c:762 [inline]
 __se_sys_ioctl+0x319/0x4d0 fs/ioctl.c:760
 __x64_sys_ioctl+0x4a/0x70 fs/ioctl.c:760
 do_syscall_64+0xad/0x160 arch/x86/entry/common.c:386
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Bytes 0-319 of 640 are uninitialized
Memory access of size 640 starts at ffff8880bbb25000
Data copied to user address 0000000020000100
=====================================================

Crashes (1254):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kmsan-gce 2020/09/06 04:03 https://github.com/google/kmsan.git master 3b3ea6028136 abf9ba4f .config log report syz C
ci-upstream-kmsan-gce 2022/05/25 13:19 https://github.com/google/kmsan.git master c5c93da9af13 647c0e27 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce 2022/05/25 09:45 https://github.com/google/kmsan.git master c5c93da9af13 647c0e27 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce 2022/05/25 02:26 https://github.com/google/kmsan.git master c5c93da9af13 647c0e27 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce 2022/05/24 01:22 https://github.com/google/kmsan.git master c5c93da9af13 e7f9308d .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce 2022/05/21 05:27 https://github.com/google/kmsan.git master c5c93da9af13 7268fa62 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce 2022/05/20 14:22 https://github.com/google/kmsan.git master c5c93da9af13 cb1ac2e7 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce 2022/05/19 14:18 https://github.com/google/kmsan.git master c5c93da9af13 50c53f39 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce 2022/05/18 23:54 https://github.com/google/kmsan.git master c5c93da9af13 50c53f39 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce 2022/05/16 19:55 https://github.com/google/kmsan.git master d6e2c8c7eb40 744a39e2 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce 2022/05/16 08:50 https://github.com/google/kmsan.git master d6e2c8c7eb40 744a39e2 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce 2022/05/16 07:45 https://github.com/google/kmsan.git master d6e2c8c7eb40 744a39e2 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce 2022/05/16 04:34 https://github.com/google/kmsan.git master d6e2c8c7eb40 744a39e2 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce 2022/05/15 23:30 https://github.com/google/kmsan.git master d6e2c8c7eb40 744a39e2 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce 2022/05/15 18:12 https://github.com/google/kmsan.git master d6e2c8c7eb40 744a39e2 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce 2022/05/15 00:01 https://github.com/google/kmsan.git master d6e2c8c7eb40 744a39e2 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce 2022/05/14 05:27 https://github.com/google/kmsan.git master d6e2c8c7eb40 107f6434 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce 2022/05/14 05:06 https://github.com/google/kmsan.git master d6e2c8c7eb40 107f6434 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce 2022/05/13 11:06 https://github.com/google/kmsan.git master d6e2c8c7eb40 9ad6612a .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce 2022/05/13 04:18 https://github.com/google/kmsan.git master d6e2c8c7eb40 9ad6612a .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce 2022/05/12 14:57 https://github.com/google/kmsan.git master d6e2c8c7eb40 9ad6612a .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce 2022/05/12 12:43 https://github.com/google/kmsan.git master d6e2c8c7eb40 beb0b407 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce 2022/05/12 05:41 https://github.com/google/kmsan.git master d6e2c8c7eb40 beb0b407 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce-386 2022/05/25 17:24 https://github.com/google/kmsan.git master c5c93da9af13 647c0e27 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce-386 2022/05/24 08:37 https://github.com/google/kmsan.git master c5c93da9af13 e7f9308d .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce-386 2022/05/24 06:53 https://github.com/google/kmsan.git master c5c93da9af13 e7f9308d .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce-386 2022/05/23 02:26 https://github.com/google/kmsan.git master c5c93da9af13 7268fa62 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce-386 2022/05/23 00:44 https://github.com/google/kmsan.git master c5c93da9af13 7268fa62 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce-386 2022/05/22 20:55 https://github.com/google/kmsan.git master c5c93da9af13 7268fa62 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce-386 2022/05/22 19:49 https://github.com/google/kmsan.git master c5c93da9af13 7268fa62 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce-386 2022/05/22 05:49 https://github.com/google/kmsan.git master c5c93da9af13 7268fa62 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce-386 2022/05/22 02:08 https://github.com/google/kmsan.git master c5c93da9af13 7268fa62 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce-386 2022/05/19 21:14 https://github.com/google/kmsan.git master c5c93da9af13 50c53f39 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce-386 2022/05/19 19:42 https://github.com/google/kmsan.git master c5c93da9af13 50c53f39 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce-386 2022/05/19 09:15 https://github.com/google/kmsan.git master c5c93da9af13 50c53f39 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce-386 2022/05/14 17:45 https://github.com/google/kmsan.git master d6e2c8c7eb40 744a39e2 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce-386 2022/05/12 04:12 https://github.com/google/kmsan.git master d6e2c8c7eb40 beb0b407 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce-386 2022/05/11 18:29 https://github.com/google/kmsan.git master d6e2c8c7eb40 beb0b407 .config log report info KMSAN: kernel-infoleak in vcs_read
ci-upstream-kmsan-gce 2022/05/23 11:10 https://github.com/google/kmsan.git master c5c93da9af13 4c7657cb .config log report info KMSAN: kernel-infoleak-after-free in vcs_read
ci-upstream-kmsan-gce 2022/05/23 06:31 https://github.com/google/kmsan.git master c5c93da9af13 7268fa62 .config log report info KMSAN: kernel-infoleak-after-free in vcs_read
ci-upstream-kmsan-gce 2022/05/20 17:26 https://github.com/google/kmsan.git master c5c93da9af13 bd37ad7e .config log report info KMSAN: kernel-infoleak-after-free in vcs_read
ci-upstream-kmsan-gce 2022/05/19 12:30 https://github.com/google/kmsan.git master c5c93da9af13 50c53f39 .config log report info KMSAN: kernel-infoleak-after-free in vcs_read
ci-upstream-kmsan-gce 2022/05/17 04:17 https://github.com/google/kmsan.git master d6e2c8c7eb40 744a39e2 .config log report info KMSAN: kernel-infoleak-after-free in vcs_read
ci-upstream-kmsan-gce 2022/05/15 19:41 https://github.com/google/kmsan.git master d6e2c8c7eb40 744a39e2 .config log report info KMSAN: kernel-infoleak-after-free in vcs_read
ci-upstream-kmsan-gce 2022/05/14 15:20 https://github.com/google/kmsan.git master d6e2c8c7eb40 744a39e2 .config log report info KMSAN: kernel-infoleak-after-free in vcs_read
ci-upstream-kmsan-gce 2021/01/17 13:51 https://github.com/google/kmsan.git master 73d62e81b476 813be542 .config log report info
ci-upstream-kmsan-gce 2019/12/04 14:52 https://github.com/google/kmsan.git master 141b13f7780f b2088328 .config log report
ci-upstream-kmsan-gce-386 2022/05/24 05:46 https://github.com/google/kmsan.git master c5c93da9af13 e7f9308d .config log report info KMSAN: kernel-infoleak-after-free in vcs_read
ci-upstream-kmsan-gce-386 2022/05/16 17:13 https://github.com/google/kmsan.git master d6e2c8c7eb40 744a39e2 .config log report info KMSAN: kernel-infoleak-after-free in vcs_read