KASAN: use-after-free Read in vgem_gem_dumb_create
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syzbot
Jan 31, 2020, 9:46:14 AM1/31/20
to syzkaller...@googlegroups.com
Hello,
syzbot found the following crash on:
HEAD commit: 9fa690a2 Linux 4.14.169
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16bf7735e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=eb55b601e76e3476
dashboard link: https://syzkaller.appspot.com/bug?extid=9ec06b17ace310c768e2
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10054a79e00000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+9ec06b...@syzkaller.appspotmail.com
batman_adv: batadv0: Interface activated: batadv_slave_1
IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready
==================================================================
BUG: KASAN: use-after-free in vgem_gem_dumb_create+0x20c/0x220 drivers/gpu/drm/vgem/vgem_drv.c:215
Read of size 8 at addr ffff88809bb666c0 by task syz-executor.0/9878
CPU: 1 PID: 9878 Comm: syz-executor.0 Not tainted 4.14.169-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x142/0x197 lib/dump_stack.c:58
print_address_description.cold+0x7c/0x1dc mm/kasan/report.c:252
kasan_report_error mm/kasan/report.c:351 [inline]
kasan_report mm/kasan/report.c:409 [inline]
kasan_report.cold+0xa9/0x2af mm/kasan/report.c:393
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430
vgem_gem_dumb_create+0x20c/0x220 drivers/gpu/drm/vgem/vgem_drv.c:215
drm_mode_create_dumb_ioctl+0x22c/0x2b0 drivers/gpu/drm/drm_dumb_buffers.c:92
drm_ioctl_kernel+0x154/0x210 drivers/gpu/drm/drm_ioctl.c:736
drm_ioctl+0x493/0x940 drivers/gpu/drm/drm_ioctl.c:836
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:500 [inline]
do_vfs_ioctl+0x7ae/0x1060 fs/ioctl.c:684
SYSC_ioctl fs/ioctl.c:701 [inline]
SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45b349
RSP: 002b:00007faf00514c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007faf005156d4 RCX: 000000000045b349
RDX: 0000000020000180 RSI: 00000000c02064b2 RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000285 R14: 00000000004d14d0 R15: 000000000075bf2c
Allocated by task 9878:
save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
save_stack+0x45/0xd0 mm/kasan/kasan.c:447
set_track mm/kasan/kasan.c:459 [inline]
kasan_kmalloc mm/kasan/kasan.c:551 [inline]
kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:529
kmem_cache_alloc_trace+0x152/0x790 mm/slab.c:3618
kmalloc include/linux/slab.h:488 [inline]
kzalloc include/linux/slab.h:661 [inline]
__vgem_gem_create+0x49/0xf0 drivers/gpu/drm/vgem/vgem_drv.c:159
vgem_gem_create drivers/gpu/drm/vgem/vgem_drv.c:188 [inline]
vgem_gem_dumb_create+0xcd/0x220 drivers/gpu/drm/vgem/vgem_drv.c:211
drm_mode_create_dumb_ioctl+0x22c/0x2b0 drivers/gpu/drm/drm_dumb_buffers.c:92
drm_ioctl_kernel+0x154/0x210 drivers/gpu/drm/drm_ioctl.c:736
drm_ioctl+0x493/0x940 drivers/gpu/drm/drm_ioctl.c:836
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:500 [inline]
do_vfs_ioctl+0x7ae/0x1060 fs/ioctl.c:684
SYSC_ioctl fs/ioctl.c:701 [inline]
SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
Freed by task 9878:
save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
save_stack+0x45/0xd0 mm/kasan/kasan.c:447
set_track mm/kasan/kasan.c:459 [inline]
kasan_slab_free+0x75/0xc0 mm/kasan/kasan.c:524
__cache_free mm/slab.c:3496 [inline]
kfree+0xcc/0x270 mm/slab.c:3815
vgem_gem_free_object+0xbe/0xe0 drivers/gpu/drm/vgem/vgem_drv.c:61
drm_gem_object_free+0x94/0x150 drivers/gpu/drm/drm_gem.c:838
kref_put include/linux/kref.h:70 [inline]
drm_gem_object_put_unlocked+0x12b/0x160 drivers/gpu/drm/drm_gem.c:867
vgem_gem_create drivers/gpu/drm/vgem/vgem_drv.c:193 [inline]
vgem_gem_dumb_create+0xfb/0x220 drivers/gpu/drm/vgem/vgem_drv.c:211
drm_mode_create_dumb_ioctl+0x22c/0x2b0 drivers/gpu/drm/drm_dumb_buffers.c:92
drm_ioctl_kernel+0x154/0x210 drivers/gpu/drm/drm_ioctl.c:736
drm_ioctl+0x493/0x940 drivers/gpu/drm/drm_ioctl.c:836
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:500 [inline]
do_vfs_ioctl+0x7ae/0x1060 fs/ioctl.c:684
SYSC_ioctl fs/ioctl.c:701 [inline]
SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
The buggy address belongs to the object at ffff88809bb665c0
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 256 bytes inside of
512-byte region [ffff88809bb665c0, ffff88809bb667c0)
The buggy address belongs to the page:
page:ffffea00026ed980 count:1 mapcount:0 mapping:ffff88809bb660c0 index:0x0
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffff88809bb660c0 0000000000000000 0000000100000006
raw: ffffea0002297fa0 ffffea00026cd6a0 ffff8880aa800940 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff88809bb66580: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
ffff88809bb66600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88809bb66680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88809bb66700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88809bb66780: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================
---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches
syzbot found the following crash on:
HEAD commit: 9fa690a2 Linux 4.14.169
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16bf7735e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=eb55b601e76e3476
dashboard link: https://syzkaller.appspot.com/bug?extid=9ec06b17ace310c768e2
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10054a79e00000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+9ec06b...@syzkaller.appspotmail.com
batman_adv: batadv0: Interface activated: batadv_slave_1
IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready
==================================================================
BUG: KASAN: use-after-free in vgem_gem_dumb_create+0x20c/0x220 drivers/gpu/drm/vgem/vgem_drv.c:215
Read of size 8 at addr ffff88809bb666c0 by task syz-executor.0/9878
CPU: 1 PID: 9878 Comm: syz-executor.0 Not tainted 4.14.169-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x142/0x197 lib/dump_stack.c:58
print_address_description.cold+0x7c/0x1dc mm/kasan/report.c:252
kasan_report_error mm/kasan/report.c:351 [inline]
kasan_report mm/kasan/report.c:409 [inline]
kasan_report.cold+0xa9/0x2af mm/kasan/report.c:393
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430
vgem_gem_dumb_create+0x20c/0x220 drivers/gpu/drm/vgem/vgem_drv.c:215
drm_mode_create_dumb_ioctl+0x22c/0x2b0 drivers/gpu/drm/drm_dumb_buffers.c:92
drm_ioctl_kernel+0x154/0x210 drivers/gpu/drm/drm_ioctl.c:736
drm_ioctl+0x493/0x940 drivers/gpu/drm/drm_ioctl.c:836
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:500 [inline]
do_vfs_ioctl+0x7ae/0x1060 fs/ioctl.c:684
SYSC_ioctl fs/ioctl.c:701 [inline]
SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45b349
RSP: 002b:00007faf00514c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007faf005156d4 RCX: 000000000045b349
RDX: 0000000020000180 RSI: 00000000c02064b2 RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000285 R14: 00000000004d14d0 R15: 000000000075bf2c
Allocated by task 9878:
save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
save_stack+0x45/0xd0 mm/kasan/kasan.c:447
set_track mm/kasan/kasan.c:459 [inline]
kasan_kmalloc mm/kasan/kasan.c:551 [inline]
kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:529
kmem_cache_alloc_trace+0x152/0x790 mm/slab.c:3618
kmalloc include/linux/slab.h:488 [inline]
kzalloc include/linux/slab.h:661 [inline]
__vgem_gem_create+0x49/0xf0 drivers/gpu/drm/vgem/vgem_drv.c:159
vgem_gem_create drivers/gpu/drm/vgem/vgem_drv.c:188 [inline]
vgem_gem_dumb_create+0xcd/0x220 drivers/gpu/drm/vgem/vgem_drv.c:211
drm_mode_create_dumb_ioctl+0x22c/0x2b0 drivers/gpu/drm/drm_dumb_buffers.c:92
drm_ioctl_kernel+0x154/0x210 drivers/gpu/drm/drm_ioctl.c:736
drm_ioctl+0x493/0x940 drivers/gpu/drm/drm_ioctl.c:836
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:500 [inline]
do_vfs_ioctl+0x7ae/0x1060 fs/ioctl.c:684
SYSC_ioctl fs/ioctl.c:701 [inline]
SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
Freed by task 9878:
save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
save_stack+0x45/0xd0 mm/kasan/kasan.c:447
set_track mm/kasan/kasan.c:459 [inline]
kasan_slab_free+0x75/0xc0 mm/kasan/kasan.c:524
__cache_free mm/slab.c:3496 [inline]
kfree+0xcc/0x270 mm/slab.c:3815
vgem_gem_free_object+0xbe/0xe0 drivers/gpu/drm/vgem/vgem_drv.c:61
drm_gem_object_free+0x94/0x150 drivers/gpu/drm/drm_gem.c:838
kref_put include/linux/kref.h:70 [inline]
drm_gem_object_put_unlocked+0x12b/0x160 drivers/gpu/drm/drm_gem.c:867
vgem_gem_create drivers/gpu/drm/vgem/vgem_drv.c:193 [inline]
vgem_gem_dumb_create+0xfb/0x220 drivers/gpu/drm/vgem/vgem_drv.c:211
drm_mode_create_dumb_ioctl+0x22c/0x2b0 drivers/gpu/drm/drm_dumb_buffers.c:92
drm_ioctl_kernel+0x154/0x210 drivers/gpu/drm/drm_ioctl.c:736
drm_ioctl+0x493/0x940 drivers/gpu/drm/drm_ioctl.c:836
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:500 [inline]
do_vfs_ioctl+0x7ae/0x1060 fs/ioctl.c:684
SYSC_ioctl fs/ioctl.c:701 [inline]
SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
The buggy address belongs to the object at ffff88809bb665c0
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 256 bytes inside of
512-byte region [ffff88809bb665c0, ffff88809bb667c0)
The buggy address belongs to the page:
page:ffffea00026ed980 count:1 mapcount:0 mapping:ffff88809bb660c0 index:0x0
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffff88809bb660c0 0000000000000000 0000000100000006
raw: ffffea0002297fa0 ffffea00026cd6a0 ffff8880aa800940 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff88809bb66580: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
ffff88809bb66600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88809bb66680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88809bb66700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88809bb66780: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================
---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches
syzbot
Jan 31, 2020, 4:57:14 PM1/31/20
to syzkaller...@googlegroups.com
Hello,
syzbot found the following crash on:
HEAD commit: 7cdefde3 Linux 4.19.100
syzbot found the following crash on:
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=12c71279e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=78c8736935e5597
dashboard link: https://syzkaller.appspot.com/bug?extid=5d2f824511906443deae
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=120198d9e00000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
IPv6: ADDRCONF(NETDEV_UP): batadv_slave_1: link is not ready
batman_adv: batadv0: Interface activated: batadv_slave_1
IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready
==================================================================
BUG: KASAN: use-after-free in vgem_gem_dumb_create+0x238/0x250 drivers/gpu/drm/vgem/vgem_drv.c:214
IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready
==================================================================
Read of size 8 at addr ffff88808e3b4e40 by task syz-executor.2/8757
CPU: 1 PID: 8757 Comm: syz-executor.2 Not tainted 4.19.100-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]
Call Trace:
dump_stack+0x197/0x210 lib/dump_stack.c:118
? vgem_gem_dumb_crea
syzbot
Apr 10, 2020, 1:41:11 AM4/10/20
to syzkaller...@googlegroups.com
syzbot has found a reproducer for the following crash on:
HEAD commit: dda0e292 Linux 4.19.114
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=13822a3be00000
kernel config: https://syzkaller.appspot.com/x/.config?x=f32ac7e5b2d5c341
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=118a73c7e00000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+5d2f82...@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: use-after-free in vgem_gem_dumb_create+0x22c/0x240 drivers/gpu/drm/vgem/vgem_drv.c:214
Read of size 8 at addr ffff8880961deb00 by task syz-executor195/13541
CPU: 0 PID: 13541 Comm: syz-executor195 Not tainted 4.19.114-syzkaller #0
print_address_description.cold+0x7c/0x212 mm/kasan/report.c:256
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report mm/kasan/report.c:412 [inline]
kasan_report.cold+0x88/0x2b9 mm/kasan/report.c:396
vgem_gem_dumb_create+0x22c/0x240 drivers/gpu/drm/vgem/vgem_drv.c:214
drm_mode_create_dumb+0x27c/0x300 drivers/gpu/drm/drm_dumb_buffers.c:92
drm_ioctl_kernel+0x1ef/0x2a0 drivers/gpu/drm/drm_ioctl.c:752
drm_ioctl+0x4c4/0x96c drivers/gpu/drm/drm_ioctl.c:852
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0xcda/0x12e0 fs/ioctl.c:688
ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
__do_sys_ioctl fs/ioctl.c:712 [inline]
__se_sys_ioctl fs/ioctl.c:710 [inline]
__x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x44a799
Code: e8 5c b3 02 00 48 83 c4 18 c3 0f 1f 80 00 00 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 0f 83 2b cc fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fb087644d18 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000006dbc48 RCX: 000000000044a799
RDX: 0000000020000280 RSI: 00000000c02064b2 RDI: 0000000000000008
RBP: 00000000006dbc40 R08: 65732f636f72702f R09: 65732f636f72702f
R10: 65732f636f72702f R11: 0000000000000246 R12: 00000000006dbc4c
R13: 00007fb087644d20 R14: 00007fb087644d20 R15: 20c49ba5e353f7cf
Allocated by task 13541:
set_track mm/kasan/kasan.c:460 [inline]
kasan_kmalloc mm/kasan/kasan.c:553 [inline]
kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:531
kmem_cache_alloc_trace+0x14d/0x7a0 mm/slab.c:3625
kmalloc include/linux/slab.h:515 [inline]
kzalloc include/linux/slab.h:709 [inline]
__vgem_gem_create+0x44/0xf0 drivers/gpu/drm/vgem/vgem_drv.c:158
vgem_gem_create drivers/gpu/drm/vgem/vgem_drv.c:187 [inline]
vgem_gem_dumb_create+0xcf/0x240 drivers/gpu/drm/vgem/vgem_drv.c:210
drm_mode_create_dumb+0x27c/0x300 drivers/gpu/drm/drm_dumb_buffers.c:92
drm_ioctl_kernel+0x1ef/0x2a0 drivers/gpu/drm/drm_ioctl.c:752
drm_ioctl+0x4c4/0x96c drivers/gpu/drm/drm_ioctl.c:852
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0xcda/0x12e0 fs/ioctl.c:688
ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
__do_sys_ioctl fs/ioctl.c:712 [inline]
__se_sys_ioctl fs/ioctl.c:710 [inline]
__x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Freed by task 13541:
set_track mm/kasan/kasan.c:460 [inline]
__kasan_slab_free+0xf7/0x140 mm/kasan/kasan.c:521
__cache_free mm/slab.c:3503 [inline]
kfree+0xce/0x220 mm/slab.c:3822
drm_gem_object_free+0x91/0x1c0 drivers/gpu/drm/drm_gem.c:839
kref_put include/linux/kref.h:70 [inline]
drm_gem_object_put_unlocked+0x14c/0x180 drivers/gpu/drm/drm_gem.c:868
vgem_gem_create drivers/gpu/drm/vgem/vgem_drv.c:192 [inline]
vgem_gem_dumb_create+0x10c/0x240 drivers/gpu/drm/vgem/vgem_drv.c:210
drm_mode_create_dumb+0x27c/0x300 drivers/gpu/drm/drm_dumb_buffers.c:92
drm_ioctl_kernel+0x1ef/0x2a0 drivers/gpu/drm/drm_ioctl.c:752
drm_ioctl+0x4c4/0x96c drivers/gpu/drm/drm_ioctl.c:852
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0xcda/0x12e0 fs/ioctl.c:688
ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
__do_sys_ioctl fs/ioctl.c:712 [inline]
__se_sys_ioctl fs/ioctl.c:710 [inline]
__x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
The buggy address belongs to the object at ffff8880961dea00
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffffea000283dc08 ffffea00027a1cc8 ffff88812c3dc940
raw: 0000000000000000 ffff8880961de000 0000000100000006 0000000000000000
ffff8880961dea80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880961deb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8880961deb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880961dec00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
HEAD commit: dda0e292 Linux 4.19.114
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=13822a3be00000
kernel config: https://syzkaller.appspot.com/x/.config?x=f32ac7e5b2d5c341
dashboard link: https://syzkaller.appspot.com/bug?extid=5d2f824511906443deae
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=172e61afe00000
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=118a73c7e00000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+5d2f82...@syzkaller.appspotmail.com
BUG: KASAN: use-after-free in vgem_gem_dumb_create+0x22c/0x240 drivers/gpu/drm/vgem/vgem_drv.c:214
Read of size 8 at addr ffff8880961deb00 by task syz-executor195/13541
CPU: 0 PID: 13541 Comm: syz-executor195 Not tainted 4.19.114-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+0x188/0x20d lib/dump_stack.c:118
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
print_address_description.cold+0x7c/0x212 mm/kasan/report.c:256
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report mm/kasan/report.c:412 [inline]
kasan_report.cold+0x88/0x2b9 mm/kasan/report.c:396
vgem_gem_dumb_create+0x22c/0x240 drivers/gpu/drm/vgem/vgem_drv.c:214
drm_mode_create_dumb+0x27c/0x300 drivers/gpu/drm/drm_dumb_buffers.c:92
drm_ioctl_kernel+0x1ef/0x2a0 drivers/gpu/drm/drm_ioctl.c:752
drm_ioctl+0x4c4/0x96c drivers/gpu/drm/drm_ioctl.c:852
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0xcda/0x12e0 fs/ioctl.c:688
ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
__do_sys_ioctl fs/ioctl.c:712 [inline]
__se_sys_ioctl fs/ioctl.c:710 [inline]
__x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x44a799
Code: e8 5c b3 02 00 48 83 c4 18 c3 0f 1f 80 00 00 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 0f 83 2b cc fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fb087644d18 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000006dbc48 RCX: 000000000044a799
RDX: 0000000020000280 RSI: 00000000c02064b2 RDI: 0000000000000008
RBP: 00000000006dbc40 R08: 65732f636f72702f R09: 65732f636f72702f
R10: 65732f636f72702f R11: 0000000000000246 R12: 00000000006dbc4c
R13: 00007fb087644d20 R14: 00007fb087644d20 R15: 20c49ba5e353f7cf
Allocated by task 13541:
set_track mm/kasan/kasan.c:460 [inline]
kasan_kmalloc mm/kasan/kasan.c:553 [inline]
kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:531
kmem_cache_alloc_trace+0x14d/0x7a0 mm/slab.c:3625
kmalloc include/linux/slab.h:515 [inline]
kzalloc include/linux/slab.h:709 [inline]
__vgem_gem_create+0x44/0xf0 drivers/gpu/drm/vgem/vgem_drv.c:158
vgem_gem_create drivers/gpu/drm/vgem/vgem_drv.c:187 [inline]
vgem_gem_dumb_create+0xcf/0x240 drivers/gpu/drm/vgem/vgem_drv.c:210
drm_mode_create_dumb+0x27c/0x300 drivers/gpu/drm/drm_dumb_buffers.c:92
drm_ioctl_kernel+0x1ef/0x2a0 drivers/gpu/drm/drm_ioctl.c:752
drm_ioctl+0x4c4/0x96c drivers/gpu/drm/drm_ioctl.c:852
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0xcda/0x12e0 fs/ioctl.c:688
ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
__do_sys_ioctl fs/ioctl.c:712 [inline]
__se_sys_ioctl fs/ioctl.c:710 [inline]
__x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Freed by task 13541:
set_track mm/kasan/kasan.c:460 [inline]
__kasan_slab_free+0xf7/0x140 mm/kasan/kasan.c:521
__cache_free mm/slab.c:3503 [inline]
kfree+0xce/0x220 mm/slab.c:3822
drm_gem_object_free+0x91/0x1c0 drivers/gpu/drm/drm_gem.c:839
kref_put include/linux/kref.h:70 [inline]
drm_gem_object_put_unlocked+0x14c/0x180 drivers/gpu/drm/drm_gem.c:868
vgem_gem_create drivers/gpu/drm/vgem/vgem_drv.c:192 [inline]
vgem_gem_dumb_create+0x10c/0x240 drivers/gpu/drm/vgem/vgem_drv.c:210
drm_mode_create_dumb+0x27c/0x300 drivers/gpu/drm/drm_dumb_buffers.c:92
drm_ioctl_kernel+0x1ef/0x2a0 drivers/gpu/drm/drm_ioctl.c:752
drm_ioctl+0x4c4/0x96c drivers/gpu/drm/drm_ioctl.c:852
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0xcda/0x12e0 fs/ioctl.c:688
ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
__do_sys_ioctl fs/ioctl.c:712 [inline]
__se_sys_ioctl fs/ioctl.c:710 [inline]
__x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
The buggy address belongs to the object at ffff8880961dea00
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 256 bytes inside of
512-byte region [ffff8880961dea00, ffff8880961dec00)
The buggy address is located 256 bytes inside of
The buggy address belongs to the page:
page:ffffea0002587780 count:1 mapcount:0 mapping:ffff88812c3dc940 index:0x0
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffffea000283dc08 ffffea00027a1cc8 ffff88812c3dc940
raw: 0000000000000000 ffff8880961de000 0000000100000006 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8880961dea00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
Memory state around the buggy address:
ffff8880961dea80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880961deb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8880961deb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880961dec00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
syzbot
Aug 31, 2020, 5:49:16 AM8/31/20
to syzkaller...@googlegroups.com
syzbot has found a reproducer for the following issue on:
HEAD commit: d7e78d08 Linux 4.14.195
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=11f8a271900000
kernel config: https://syzkaller.appspot.com/x/.config?x=6608b656f49b4e8c
dashboard link: https://syzkaller.appspot.com/bug?extid=9ec06b17ace310c768e2
compiler: gcc (GCC) 10.1.0-syz 20200507
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17eff38e900000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=127356c1900000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9ec06b...@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: use-after-free in vgem_gem_dumb_create+0x200/0x210 drivers/gpu/drm/vgem/vgem_drv.c:215
Read of size 8 at addr ffff888090c133c0 by task syz-executor231/18285
CPU: 0 PID: 18285 Comm: syz-executor231 Not tainted 4.14.195-syzkaller #0
print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252
kasan_report_error.cold+0x8a/0x194 mm/kasan/report.c:351
kasan_report mm/kasan/report.c:409 [inline]
__asan_report_load8_noabort+0x68/0x70 mm/kasan/report.c:430
vgem_gem_dumb_create+0x200/0x210 drivers/gpu/drm/vgem/vgem_drv.c:215
drm_mode_create_dumb_ioctl+0x221/0x2b0 drivers/gpu/drm/drm_dumb_buffers.c:92
drm_ioctl_kernel+0x14c/0x200 drivers/gpu/drm/drm_ioctl.c:736
drm_ioctl+0x419/0x870 drivers/gpu/drm/drm_ioctl.c:836
SYSC_ioctl fs/ioctl.c:701 [inline]
SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x44b049
RSP: 002b:00007fcebec13db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000006dcc78 RCX: 000000000044b049
RDX: 00000000200000c0 RSI: 00000000c02064b2 RDI: 0000000000000003
RBP: 00000000006dcc70 R08: 0000000000000000 R09: 0000000000000000
R10: 00007fcebec14700 R11: 0000000000000246 R12: 00000000006dcc7c
R13: 00007ffdecc6892f R14: 00007fcebec149c0 R15: 0000000000000001
Allocated by task 18285:
save_stack mm/kasan/kasan.c:447 [inline]
set_track mm/kasan/kasan.c:459 [inline]
kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551
kmem_cache_alloc_trace+0x131/0x3d0 mm/slab.c:3618
vgem_gem_create drivers/gpu/drm/vgem/vgem_drv.c:188 [inline]
vgem_gem_dumb_create+0xc5/0x210 drivers/gpu/drm/vgem/vgem_drv.c:211
drm_mode_create_dumb_ioctl+0x221/0x2b0 drivers/gpu/drm/drm_dumb_buffers.c:92
drm_ioctl_kernel+0x14c/0x200 drivers/gpu/drm/drm_ioctl.c:736
drm_ioctl+0x419/0x870 drivers/gpu/drm/drm_ioctl.c:836
SYSC_ioctl fs/ioctl.c:701 [inline]
SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
Freed by task 18285:
save_stack mm/kasan/kasan.c:447 [inline]
set_track mm/kasan/kasan.c:459 [inline]
kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524
__cache_free mm/slab.c:3496 [inline]
kfree+0xc9/0x250 mm/slab.c:3815
drm_gem_object_free+0x8f/0x150 drivers/gpu/drm/drm_gem.c:836
kref_put include/linux/kref.h:70 [inline]
drm_gem_object_put_unlocked+0xc3/0x160 drivers/gpu/drm/drm_gem.c:865
vgem_gem_create drivers/gpu/drm/vgem/vgem_drv.c:193 [inline]
vgem_gem_dumb_create+0xf2/0x210 drivers/gpu/drm/vgem/vgem_drv.c:211
drm_mode_create_dumb_ioctl+0x221/0x2b0 drivers/gpu/drm/drm_dumb_buffers.c:92
drm_ioctl_kernel+0x14c/0x200 drivers/gpu/drm/drm_ioctl.c:736
drm_ioctl+0x419/0x870 drivers/gpu/drm/drm_ioctl.c:836
SYSC_ioctl fs/ioctl.c:701 [inline]
SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
The buggy address belongs to the object at ffff888090c132c0
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffff888090c13040 0000000000000000 0000000100000006
raw: ffffea0002a1c360 ffffea00027957e0 ffff88812fe52940 0000000000000000
ffff888090c13300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888090c13380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888090c13400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888090c13480: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================
HEAD commit: d7e78d08 Linux 4.14.195
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=11f8a271900000
kernel config: https://syzkaller.appspot.com/x/.config?x=6608b656f49b4e8c
dashboard link: https://syzkaller.appspot.com/bug?extid=9ec06b17ace310c768e2
compiler: gcc (GCC) 10.1.0-syz 20200507
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17eff38e900000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=127356c1900000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9ec06b...@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: use-after-free in vgem_gem_dumb_create+0x200/0x210 drivers/gpu/drm/vgem/vgem_drv.c:215
Read of size 8 at addr ffff888090c133c0 by task syz-executor231/18285
CPU: 0 PID: 18285 Comm: syz-executor231 Not tainted 4.14.195-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x1b2/0x283 lib/dump_stack.c:58
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252
kasan_report_error.cold+0x8a/0x194 mm/kasan/report.c:351
kasan_report mm/kasan/report.c:409 [inline]
__asan_report_load8_noabort+0x68/0x70 mm/kasan/report.c:430
vgem_gem_dumb_create+0x200/0x210 drivers/gpu/drm/vgem/vgem_drv.c:215
drm_mode_create_dumb_ioctl+0x221/0x2b0 drivers/gpu/drm/drm_dumb_buffers.c:92
drm_ioctl_kernel+0x14c/0x200 drivers/gpu/drm/drm_ioctl.c:736
drm_ioctl+0x419/0x870 drivers/gpu/drm/drm_ioctl.c:836
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:500 [inline]
do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684
file_ioctl fs/ioctl.c:500 [inline]
SYSC_ioctl fs/ioctl.c:701 [inline]
SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x44b049
RSP: 002b:00007fcebec13db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000006dcc78 RCX: 000000000044b049
RDX: 00000000200000c0 RSI: 00000000c02064b2 RDI: 0000000000000003
RBP: 00000000006dcc70 R08: 0000000000000000 R09: 0000000000000000
R10: 00007fcebec14700 R11: 0000000000000246 R12: 00000000006dcc7c
R13: 00007ffdecc6892f R14: 00007fcebec149c0 R15: 0000000000000001
Allocated by task 18285:
save_stack mm/kasan/kasan.c:447 [inline]
set_track mm/kasan/kasan.c:459 [inline]
kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551
kmem_cache_alloc_trace+0x131/0x3d0 mm/slab.c:3618
kmalloc include/linux/slab.h:488 [inline]
kzalloc include/linux/slab.h:661 [inline]
__vgem_gem_create+0x44/0xe0 drivers/gpu/drm/vgem/vgem_drv.c:159
kzalloc include/linux/slab.h:661 [inline]
vgem_gem_create drivers/gpu/drm/vgem/vgem_drv.c:188 [inline]
vgem_gem_dumb_create+0xc5/0x210 drivers/gpu/drm/vgem/vgem_drv.c:211
drm_mode_create_dumb_ioctl+0x221/0x2b0 drivers/gpu/drm/drm_dumb_buffers.c:92
drm_ioctl_kernel+0x14c/0x200 drivers/gpu/drm/drm_ioctl.c:736
drm_ioctl+0x419/0x870 drivers/gpu/drm/drm_ioctl.c:836
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:500 [inline]
do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684
file_ioctl fs/ioctl.c:500 [inline]
SYSC_ioctl fs/ioctl.c:701 [inline]
SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
Freed by task 18285:
save_stack mm/kasan/kasan.c:447 [inline]
set_track mm/kasan/kasan.c:459 [inline]
kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524
__cache_free mm/slab.c:3496 [inline]
kfree+0xc9/0x250 mm/slab.c:3815
drm_gem_object_free+0x8f/0x150 drivers/gpu/drm/drm_gem.c:836
kref_put include/linux/kref.h:70 [inline]
drm_gem_object_put_unlocked+0xc3/0x160 drivers/gpu/drm/drm_gem.c:865
vgem_gem_create drivers/gpu/drm/vgem/vgem_drv.c:193 [inline]
vgem_gem_dumb_create+0xf2/0x210 drivers/gpu/drm/vgem/vgem_drv.c:211
drm_mode_create_dumb_ioctl+0x221/0x2b0 drivers/gpu/drm/drm_dumb_buffers.c:92
drm_ioctl_kernel+0x14c/0x200 drivers/gpu/drm/drm_ioctl.c:736
drm_ioctl+0x419/0x870 drivers/gpu/drm/drm_ioctl.c:836
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:500 [inline]
do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684
file_ioctl fs/ioctl.c:500 [inline]
SYSC_ioctl fs/ioctl.c:701 [inline]
SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
The buggy address belongs to the object at ffff888090c132c0
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 256 bytes inside of
512-byte region [ffff888090c132c0, ffff888090c134c0)
The buggy address is located 256 bytes inside of
The buggy address belongs to the page:
page:ffffea00024304c0 count:1 mapcount:0 mapping:ffff888090c13040 index:0x0
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffff888090c13040 0000000000000000 0000000100000006
raw: ffffea0002a1c360 ffffea00027957e0 ffff88812fe52940 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888090c13280: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
Memory state around the buggy address:
ffff888090c13300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888090c13380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888090c13400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888090c13480: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================
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