Re: [PATCH -next] vgacon: Fix an out-of-bounds in vgacon_scrollback_update()
Hi, Please re-send adding the correct mailing lists: * dri-de...@lists.freedesktop.org * linux-fb...@vger.kernel.org to Cc: so the patch can be reviewed/merged. Best regards, -- Bartlomiej Zolnierkiewicz Samsung R Institute Poland Samsung Electronics On 5/13/20 4:28 AM, Yang Yingliang wrote: > I got a slab-out-of-bounds report when I doing fuzz test. > > [ 334.989515] > == > [ 334.989577] BUG: KASAN: slab-out-of-bounds in vgacon_scroll+0x57a/0x8ed > [ 334.989588] Write of size 1766 at addr 8883de69ff3e by task test/2658 > [ 334.989593] > [ 334.989608] CPU: 3 PID: 2658 Comm: test Not tainted > 5.7.0-rc5-5-g152036d1379f #789 > [ 334.989617] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 > [ 334.989624] Call Trace: > [ 334.989646] dump_stack+0xe4/0x14e > [ 334.989676] print_address_description.constprop.5+0x3f/0x60 > [ 334.989699] ? vgacon_scroll+0x57a/0x8ed > [ 334.989710] __kasan_report.cold.8+0x92/0xaf > [ 334.989735] ? vgacon_scroll+0x57a/0x8ed > [ 334.989761] kasan_report+0x37/0x50 > [ 334.989789] check_memory_region+0x1c1/0x1e0 > [ 334.989806] memcpy+0x38/0x60 > [ 334.989824] vgacon_scroll+0x57a/0x8ed > [ 334.989876] con_scroll+0x4ef/0x5e0 > [ 334.989904] ? lockdep_hardirqs_on+0x5e0/0x5e0 > [ 334.989934] lf+0x24f/0x2a0 > [ 334.989951] ? con_scroll+0x5e0/0x5e0 > [ 334.989975] ? find_held_lock+0x33/0x1c0 > [ 334.990005] do_con_trol+0x313/0x5ff0 > [ 334.990027] ? lock_downgrade+0x730/0x730 > [ 334.990045] ? reset_palette+0x440/0x440 > [ 334.990070] ? _raw_spin_unlock_irqrestore+0x4b/0x60 > [ 334.990095] ? notifier_call_chain+0x120/0x170 > [ 334.990132] ? __atomic_notifier_call_chain+0xf0/0x180 > [ 334.990160] do_con_write.part.16+0xb2b/0x1b20 > [ 334.990238] ? do_con_trol+0x5ff0/0x5ff0 > [ 334.990258] ? mutex_lock_io_nested+0x1280/0x1280 > [ 334.990269] ? rcu_read_unlock+0x50/0x50 > [ 334.990315] ? __mutex_unlock_slowpath+0xd9/0x670 > [ 334.990340] ? lockdep_hardirqs_on+0x3a2/0x5e0 > [ 334.990368] con_write+0x36/0xc0 > [ 334.990389] do_output_char+0x561/0x780 > [ 334.990414] n_tty_write+0x58e/0xd30 > [ 334.990478] ? n_tty_read+0x1800/0x1800 > [ 334.990500] ? prepare_to_wait_exclusive+0x300/0x300 > [ 334.990525] ? __might_fault+0x17a/0x1c0 > [ 334.990557] tty_write+0x430/0x960 > [ 334.990568] ? n_tty_read+0x1800/0x1800 > [ 334.990600] ? tty_release+0x1280/0x1280 > [ 334.990622] __vfs_write+0x81/0x100 > [ 334.990648] vfs_write+0x1ce/0x510 > [ 334.990676] ksys_write+0x104/0x200 > [ 334.990691] ? __ia32_sys_read+0xb0/0xb0 > [ 334.990708] ? trace_hardirqs_on_thunk+0x1a/0x1c > [ 334.990725] ? trace_hardirqs_off_caller+0x40/0x1a0 > [ 334.990744] ? do_syscall_64+0x3b/0x5e0 > [ 334.990775] do_syscall_64+0xc8/0x5e0 > [ 334.990798] entry_SYSCALL_64_after_hwframe+0x49/0xb3 > [ 334.990811] RIP: 0033:0x44f369 > [ 334.990827] Code: 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 c0 ff ff ff f7 d8 64 89 01 48 > [ 334.990834] RSP: 002b:7ffe9ace0968 EFLAGS: 0246 ORIG_RAX: > 0001 > [ 334.990848] RAX: ffda RBX: 00400418 RCX: > 0044f369 > [ 334.990856] RDX: 0381 RSI: 20003500 RDI: > 0003 > [ 334.990865] RBP: 7ffe9ace0980 R08: 20003530 R09: > 7ffe9ace0980 > [ 334.990873] R10: 0001 R11: 0246 R12: > 00402110 > [ 334.990881] R13: R14: 006bf018 R15: > > [ 334.990937] > [ 334.990943] The buggy address belongs to the page: > [ 334.990962] page:ea000f79a400 refcount:1 mapcount:0 > mapping:2bff47b3 index:0x0 head:ea000f79a400 order:4 > compound_mapcount:0 compound_pincount:0 > [ 334.990973] flags: 0x2f8001(head) > [ 334.990992] raw: 002f8001 dead0100 dead0122 > > [ 334.991006] raw: 0001 > > [ 334.991013] page dumped because: kasan: bad access detected > [ 334.991017] > [ 334.991023] Memory state around the buggy address: > [ 334.991034] 8883de6a: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 00 00 > [ 334.991044] 8883de6a0080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 00 00 > [ 334.991054] >8883de6a0100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > fc fc > [ 334.991061] ^ > [ 334.991071] 8883de6a0180: fc fc fc fc fc fc 00 00 00 00 00 00 00 00 > 00 00 > [ 334.991082] 8883de6a0200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 00 00 > [ 334.991088] > == > > Because vgacon_scrollback_cur->tail
Re: [PATCH -next] vgacon: Fix an out-of-bounds in vgacon_scrollback_update()
ping On 2020/5/13 10:28, Yang Yingliang wrote: I got a slab-out-of-bounds report when I doing fuzz test. [ 334.989515] == [ 334.989577] BUG: KASAN: slab-out-of-bounds in vgacon_scroll+0x57a/0x8ed [ 334.989588] Write of size 1766 at addr 8883de69ff3e by task test/2658 [ 334.989593] [ 334.989608] CPU: 3 PID: 2658 Comm: test Not tainted 5.7.0-rc5-5-g152036d1379f #789 [ 334.989617] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 [ 334.989624] Call Trace: [ 334.989646] dump_stack+0xe4/0x14e [ 334.989676] print_address_description.constprop.5+0x3f/0x60 [ 334.989699] ? vgacon_scroll+0x57a/0x8ed [ 334.989710] __kasan_report.cold.8+0x92/0xaf [ 334.989735] ? vgacon_scroll+0x57a/0x8ed [ 334.989761] kasan_report+0x37/0x50 [ 334.989789] check_memory_region+0x1c1/0x1e0 [ 334.989806] memcpy+0x38/0x60 [ 334.989824] vgacon_scroll+0x57a/0x8ed [ 334.989876] con_scroll+0x4ef/0x5e0 [ 334.989904] ? lockdep_hardirqs_on+0x5e0/0x5e0 [ 334.989934] lf+0x24f/0x2a0 [ 334.989951] ? con_scroll+0x5e0/0x5e0 [ 334.989975] ? find_held_lock+0x33/0x1c0 [ 334.990005] do_con_trol+0x313/0x5ff0 [ 334.990027] ? lock_downgrade+0x730/0x730 [ 334.990045] ? reset_palette+0x440/0x440 [ 334.990070] ? _raw_spin_unlock_irqrestore+0x4b/0x60 [ 334.990095] ? notifier_call_chain+0x120/0x170 [ 334.990132] ? __atomic_notifier_call_chain+0xf0/0x180 [ 334.990160] do_con_write.part.16+0xb2b/0x1b20 [ 334.990238] ? do_con_trol+0x5ff0/0x5ff0 [ 334.990258] ? mutex_lock_io_nested+0x1280/0x1280 [ 334.990269] ? rcu_read_unlock+0x50/0x50 [ 334.990315] ? __mutex_unlock_slowpath+0xd9/0x670 [ 334.990340] ? lockdep_hardirqs_on+0x3a2/0x5e0 [ 334.990368] con_write+0x36/0xc0 [ 334.990389] do_output_char+0x561/0x780 [ 334.990414] n_tty_write+0x58e/0xd30 [ 334.990478] ? n_tty_read+0x1800/0x1800 [ 334.990500] ? prepare_to_wait_exclusive+0x300/0x300 [ 334.990525] ? __might_fault+0x17a/0x1c0 [ 334.990557] tty_write+0x430/0x960 [ 334.990568] ? n_tty_read+0x1800/0x1800 [ 334.990600] ? tty_release+0x1280/0x1280 [ 334.990622] __vfs_write+0x81/0x100 [ 334.990648] vfs_write+0x1ce/0x510 [ 334.990676] ksys_write+0x104/0x200 [ 334.990691] ? __ia32_sys_read+0xb0/0xb0 [ 334.990708] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 334.990725] ? trace_hardirqs_off_caller+0x40/0x1a0 [ 334.990744] ? do_syscall_64+0x3b/0x5e0 [ 334.990775] do_syscall_64+0xc8/0x5e0 [ 334.990798] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 334.990811] RIP: 0033:0x44f369 [ 334.990827] Code: 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 c0 ff ff ff f7 d8 64 89 01 48 [ 334.990834] RSP: 002b:7ffe9ace0968 EFLAGS: 0246 ORIG_RAX: 0001 [ 334.990848] RAX: ffda RBX: 00400418 RCX: 0044f369 [ 334.990856] RDX: 0381 RSI: 20003500 RDI: 0003 [ 334.990865] RBP: 7ffe9ace0980 R08: 20003530 R09: 7ffe9ace0980 [ 334.990873] R10: 0001 R11: 0246 R12: 00402110 [ 334.990881] R13: R14: 006bf018 R15: [ 334.990937] [ 334.990943] The buggy address belongs to the page: [ 334.990962] page:ea000f79a400 refcount:1 mapcount:0 mapping:2bff47b3 index:0x0 head:ea000f79a400 order:4 compound_mapcount:0 compound_pincount:0 [ 334.990973] flags: 0x2f8001(head) [ 334.990992] raw: 002f8001 dead0100 dead0122 [ 334.991006] raw: 0001 [ 334.991013] page dumped because: kasan: bad access detected [ 334.991017] [ 334.991023] Memory state around the buggy address: [ 334.991034] 8883de6a: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 334.991044] 8883de6a0080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 334.991054] >8883de6a0100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc [ 334.991061] ^ [ 334.991071] 8883de6a0180: fc fc fc fc fc fc 00 00 00 00 00 00 00 00 00 00 [ 334.991082] 8883de6a0200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 334.991088] == Because vgacon_scrollback_cur->tail plus memcpy size is greater than vgacon_scrollback_cur->size. Fix this by checking the memcpy size. Reported-by: Hulk Robot Signed-off-by: Yang Yingliang --- drivers/video/console/vgacon.c | 11 --- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c index 998b0de1812f..b51ffb9a208d 100644 --- a/drivers/video/console/vgacon.c +++ b/drivers/video/console/vgacon.c @@
[PATCH -next] vgacon: Fix an out-of-bounds in vgacon_scrollback_update()
I got a slab-out-of-bounds report when I doing fuzz test. [ 334.989515] == [ 334.989577] BUG: KASAN: slab-out-of-bounds in vgacon_scroll+0x57a/0x8ed [ 334.989588] Write of size 1766 at addr 8883de69ff3e by task test/2658 [ 334.989593] [ 334.989608] CPU: 3 PID: 2658 Comm: test Not tainted 5.7.0-rc5-5-g152036d1379f #789 [ 334.989617] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 [ 334.989624] Call Trace: [ 334.989646] dump_stack+0xe4/0x14e [ 334.989676] print_address_description.constprop.5+0x3f/0x60 [ 334.989699] ? vgacon_scroll+0x57a/0x8ed [ 334.989710] __kasan_report.cold.8+0x92/0xaf [ 334.989735] ? vgacon_scroll+0x57a/0x8ed [ 334.989761] kasan_report+0x37/0x50 [ 334.989789] check_memory_region+0x1c1/0x1e0 [ 334.989806] memcpy+0x38/0x60 [ 334.989824] vgacon_scroll+0x57a/0x8ed [ 334.989876] con_scroll+0x4ef/0x5e0 [ 334.989904] ? lockdep_hardirqs_on+0x5e0/0x5e0 [ 334.989934] lf+0x24f/0x2a0 [ 334.989951] ? con_scroll+0x5e0/0x5e0 [ 334.989975] ? find_held_lock+0x33/0x1c0 [ 334.990005] do_con_trol+0x313/0x5ff0 [ 334.990027] ? lock_downgrade+0x730/0x730 [ 334.990045] ? reset_palette+0x440/0x440 [ 334.990070] ? _raw_spin_unlock_irqrestore+0x4b/0x60 [ 334.990095] ? notifier_call_chain+0x120/0x170 [ 334.990132] ? __atomic_notifier_call_chain+0xf0/0x180 [ 334.990160] do_con_write.part.16+0xb2b/0x1b20 [ 334.990238] ? do_con_trol+0x5ff0/0x5ff0 [ 334.990258] ? mutex_lock_io_nested+0x1280/0x1280 [ 334.990269] ? rcu_read_unlock+0x50/0x50 [ 334.990315] ? __mutex_unlock_slowpath+0xd9/0x670 [ 334.990340] ? lockdep_hardirqs_on+0x3a2/0x5e0 [ 334.990368] con_write+0x36/0xc0 [ 334.990389] do_output_char+0x561/0x780 [ 334.990414] n_tty_write+0x58e/0xd30 [ 334.990478] ? n_tty_read+0x1800/0x1800 [ 334.990500] ? prepare_to_wait_exclusive+0x300/0x300 [ 334.990525] ? __might_fault+0x17a/0x1c0 [ 334.990557] tty_write+0x430/0x960 [ 334.990568] ? n_tty_read+0x1800/0x1800 [ 334.990600] ? tty_release+0x1280/0x1280 [ 334.990622] __vfs_write+0x81/0x100 [ 334.990648] vfs_write+0x1ce/0x510 [ 334.990676] ksys_write+0x104/0x200 [ 334.990691] ? __ia32_sys_read+0xb0/0xb0 [ 334.990708] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 334.990725] ? trace_hardirqs_off_caller+0x40/0x1a0 [ 334.990744] ? do_syscall_64+0x3b/0x5e0 [ 334.990775] do_syscall_64+0xc8/0x5e0 [ 334.990798] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 334.990811] RIP: 0033:0x44f369 [ 334.990827] Code: 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 c0 ff ff ff f7 d8 64 89 01 48 [ 334.990834] RSP: 002b:7ffe9ace0968 EFLAGS: 0246 ORIG_RAX: 0001 [ 334.990848] RAX: ffda RBX: 00400418 RCX: 0044f369 [ 334.990856] RDX: 0381 RSI: 20003500 RDI: 0003 [ 334.990865] RBP: 7ffe9ace0980 R08: 20003530 R09: 7ffe9ace0980 [ 334.990873] R10: 0001 R11: 0246 R12: 00402110 [ 334.990881] R13: R14: 006bf018 R15: [ 334.990937] [ 334.990943] The buggy address belongs to the page: [ 334.990962] page:ea000f79a400 refcount:1 mapcount:0 mapping:2bff47b3 index:0x0 head:ea000f79a400 order:4 compound_mapcount:0 compound_pincount:0 [ 334.990973] flags: 0x2f8001(head) [ 334.990992] raw: 002f8001 dead0100 dead0122 [ 334.991006] raw: 0001 [ 334.991013] page dumped because: kasan: bad access detected [ 334.991017] [ 334.991023] Memory state around the buggy address: [ 334.991034] 8883de6a: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 334.991044] 8883de6a0080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 334.991054] >8883de6a0100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc [ 334.991061] ^ [ 334.991071] 8883de6a0180: fc fc fc fc fc fc 00 00 00 00 00 00 00 00 00 00 [ 334.991082] 8883de6a0200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 334.991088] == Because vgacon_scrollback_cur->tail plus memcpy size is greater than vgacon_scrollback_cur->size. Fix this by checking the memcpy size. Reported-by: Hulk Robot Signed-off-by: Yang Yingliang --- drivers/video/console/vgacon.c | 11 --- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c index 998b0de1812f..b51ffb9a208d 100644 --- a/drivers/video/console/vgacon.c +++ b/drivers/video/console/vgacon.c @@ -243,6 +243,7 @@ static void
