| Message ID | 1553768752-21739-1-git-send-email-mojha@codeaurora.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [RESEND,-next] Input: uinput - Avoid Use-After-Free with udev lock | expand |
Please don't consider this patch, i will send v2 of this. Thanks, Mukesh On 3/28/2019 3:55 PM, Mukesh Ojha wrote: > uinput_destroy_device() gets called from two places. In one place, > uinput_ioctl_handler() it is protected under a lock udev->mutex > but same is not true for other place inside uinput_release(). > > This can result in a race where udev device gets freed while it > is in use. > > [ 160.093398] Call trace: > [ 160.093417] kernfs_get+0x64/0x88 > [ 160.093438] kernfs_new_node+0x94/0xc8 > [ 160.093450] kernfs_create_dir_ns+0x44/0xfc > [ 160.093463] sysfs_create_dir_ns+0xa8/0x130 > [ 160.093479] kobject_add_internal+0x278/0x650 > [ 160.093491] kobject_add_varg+0xe0/0x130 > [ 160.093502] kobject_add+0x15c/0x1d0 > [ 160.093518] device_add+0x2bc/0xde0 > [ 160.093533] input_register_device+0x5f4/0xa0c > [ 160.093547] uinput_ioctl_handler+0x1184/0x2198 > [ 160.093560] uinput_ioctl+0x38/0x48 > [ 160.093573] vfs_ioctl+0x7c/0xb4 > [ 160.093585] do_vfs_ioctl+0x9ec/0x2350 > [ 160.093597] SyS_ioctl+0x6c/0xa4 > [ 160.093610] el0_svc_naked+0x34/0x38 > [ 160.093621] ---[ end trace bccf0093cda2c538 ]--- > [ 160.099041] ============================================================================= > [ 160.107459] BUG kernfs_node_cache (Tainted: G S W O ): Object already free > [ 160.115235] ----------------------------------------------------------------------------- > [ 160.115235] > [ 160.125151] Disabling lock debugging due to kernel taint > [ 160.130626] INFO: Allocated in __kernfs_new_node+0x8c/0x3c0 age=11 cpu=2 pid=7098 > [ 160.138314] kmem_cache_alloc+0x358/0x388 > [ 160.142445] __kernfs_new_node+0x8c/0x3c0 > [ 160.146590] kernfs_new_node+0x80/0xc8 > [ 160.150462] kernfs_create_dir_ns+0x44/0xfc > [ 160.154777] sysfs_create_dir_ns+0xa8/0x130 > [ 160.158416] CPU5: update max cpu_capacity 1024 > [ 160.159085] kobject_add_internal+0x278/0x650 > [ 160.163567] kobject_add_varg+0xe0/0x130 > [ 160.167606] kobject_add+0x15c/0x1d0 > [ 160.168452] CPU5: update max cpu_capacity 780 > [ 160.171287] get_device_parent+0x2d0/0x34c > [ 160.175510] device_add+0x240/0xde0 > [ 160.178371] CPU6: update max cpu_capacity 916 > [ 160.179108] input_register_device+0x5f4/0xa0c > [ 160.183686] uinput_ioctl_handler+0x1184/0x2198 > [ 160.188346] uinput_ioctl+0x38/0x48 > [ 160.191941] vfs_ioctl+0x7c/0xb4 > [ 160.195261] do_vfs_ioctl+0x9ec/0x2350 > [ 160.199111] SyS_ioctl+0x6c/0xa4 > [ 160.202436] INFO: Freed in kernfs_put+0x2c8/0x434 age=14 cpu=0 pid=7096 > [ 160.209230] kernfs_put+0x2c8/0x434 > [ 160.212825] kobject_del+0x50/0xcc > [ 160.216332] cleanup_glue_dir+0x124/0x16c > [ 160.220456] device_del+0x55c/0x5c8 > [ 160.224047] __input_unregister_device+0x274/0x2a8 > [ 160.228974] input_unregister_device+0x90/0xd0 > [ 160.233553] uinput_destroy_device+0x15c/0x1dc > [ 160.238131] uinput_release+0x44/0x5c > [ 160.241898] __fput+0x1f4/0x4e4 > [ 160.245127] ____fput+0x20/0x2c > [ 160.248358] task_work_run+0x9c/0x174 > [ 160.252127] do_notify_resume+0x104/0x6bc > [ 160.256253] work_pending+0x8/0x14 > [ 160.259751] INFO: Slab 0xffffffbf0215ff00 objects=33 used=11 fp=0xffffffc0857ffd08 flags=0x8101 > [ 160.268693] INFO: Object 0xffffffc0857ffd08 @offset=15624 fp=0xffffffc0857fefb0 > [ 160.268693] > [ 160.277721] Redzone ffffffc0857ffd00: bb bb bb bb bb bb bb bb ........ > [ 160.286656] Object ffffffc0857ffd08: 00 00 00 00 01 00 00 80 58 a2 37 45 c1 ff ff ff ........X.7E.... > [ 160.296207] Object ffffffc0857ffd18: ae 21 10 0b 90 ff ff ff 20 fd 7f 85 c0 ff ff ff .!...... ....... > [ 160.305780] Object ffffffc0857ffd28: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > [ 160.315342] Object ffffffc0857ffd38: 00 00 00 00 00 00 00 00 7d a3 25 69 00 00 00 00 ........}.%i.... > [ 160.324896] Object ffffffc0857ffd48: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > [ 160.334446] Object ffffffc0857ffd58: 80 c0 28 47 c1 ff ff ff 00 00 00 00 00 00 00 00 ..(G............ > [ 160.344000] Object ffffffc0857ffd68: 80 4a ce d1 c0 ff ff ff dc 32 01 00 01 00 00 00 .J.......2...... > [ 160.353554] Object ffffffc0857ffd78: 11 00 ed 41 00 00 00 00 00 00 00 00 00 00 00 00 ...A............ > [ 160.363099] Redzone ffffffc0857ffd88: bb bb bb bb bb bb bb bb ........ > [ 160.372032] Padding ffffffc0857ffee0: 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZ > [ 160.378299] CPU6: update max cpu_capacity 780 > [ 160.380971] CPU: 4 PID: 7098 Comm: syz-executor Tainted: G S B W O 4.14.98+ #1 > > So, avoid the race by taking a udev lock inside `uinput_release()`. > > Change-Id: I3bbb07589b7b6e0e1b3bea572b5eb4f6b09774d6 > Signed-off-by: Mukesh Ojha <mojha@codeaurora.org> > Cc: Gaurav Kohli <gkohli@codeaurora.org> > Cc: Peter Hutterer <peter.hutterer@who-t.net> > Cc: Martin Kepplinger <martink@posteo.de> > Cc: "Paul E. McKenney" <paulmck@linux.ibm.com> > > --- > drivers/input/misc/uinput.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c > index 26ec603f..a3fb3b1 100644 > --- a/drivers/input/misc/uinput.c > +++ b/drivers/input/misc/uinput.c > @@ -714,9 +714,15 @@ static __poll_t uinput_poll(struct file *file, poll_table *wait) > static int uinput_release(struct inode *inode, struct file *file) > { > struct uinput_device *udev = file->private_data; > + ssize_t retval; > + > + retval = mutex_lock_interruptible(&udev->mutex); > + if (retval) > + return retval; > > uinput_destroy_device(udev); > kfree(udev); > + mutex_unlock(&udev->mutex); > > return 0; > }
diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c index 26ec603f..a3fb3b1 100644 --- a/drivers/input/misc/uinput.c +++ b/drivers/input/misc/uinput.c @@ -714,9 +714,15 @@ static __poll_t uinput_poll(struct file *file, poll_table *wait) static int uinput_release(struct inode *inode, struct file *file) { struct uinput_device *udev = file->private_data; + ssize_t retval; + + retval = mutex_lock_interruptible(&udev->mutex); + if (retval) + return retval; uinput_destroy_device(udev); kfree(udev); + mutex_unlock(&udev->mutex); return 0; }
uinput_destroy_device() gets called from two places. In one place, uinput_ioctl_handler() it is protected under a lock udev->mutex but same is not true for other place inside uinput_release(). This can result in a race where udev device gets freed while it is in use. [ 160.093398] Call trace: [ 160.093417] kernfs_get+0x64/0x88 [ 160.093438] kernfs_new_node+0x94/0xc8 [ 160.093450] kernfs_create_dir_ns+0x44/0xfc [ 160.093463] sysfs_create_dir_ns+0xa8/0x130 [ 160.093479] kobject_add_internal+0x278/0x650 [ 160.093491] kobject_add_varg+0xe0/0x130 [ 160.093502] kobject_add+0x15c/0x1d0 [ 160.093518] device_add+0x2bc/0xde0 [ 160.093533] input_register_device+0x5f4/0xa0c [ 160.093547] uinput_ioctl_handler+0x1184/0x2198 [ 160.093560] uinput_ioctl+0x38/0x48 [ 160.093573] vfs_ioctl+0x7c/0xb4 [ 160.093585] do_vfs_ioctl+0x9ec/0x2350 [ 160.093597] SyS_ioctl+0x6c/0xa4 [ 160.093610] el0_svc_naked+0x34/0x38 [ 160.093621] ---[ end trace bccf0093cda2c538 ]--- [ 160.099041] ============================================================================= [ 160.107459] BUG kernfs_node_cache (Tainted: G S W O ): Object already free [ 160.115235] ----------------------------------------------------------------------------- [ 160.115235] [ 160.125151] Disabling lock debugging due to kernel taint [ 160.130626] INFO: Allocated in __kernfs_new_node+0x8c/0x3c0 age=11 cpu=2 pid=7098 [ 160.138314] kmem_cache_alloc+0x358/0x388 [ 160.142445] __kernfs_new_node+0x8c/0x3c0 [ 160.146590] kernfs_new_node+0x80/0xc8 [ 160.150462] kernfs_create_dir_ns+0x44/0xfc [ 160.154777] sysfs_create_dir_ns+0xa8/0x130 [ 160.158416] CPU5: update max cpu_capacity 1024 [ 160.159085] kobject_add_internal+0x278/0x650 [ 160.163567] kobject_add_varg+0xe0/0x130 [ 160.167606] kobject_add+0x15c/0x1d0 [ 160.168452] CPU5: update max cpu_capacity 780 [ 160.171287] get_device_parent+0x2d0/0x34c [ 160.175510] device_add+0x240/0xde0 [ 160.178371] CPU6: update max cpu_capacity 916 [ 160.179108] input_register_device+0x5f4/0xa0c [ 160.183686] uinput_ioctl_handler+0x1184/0x2198 [ 160.188346] uinput_ioctl+0x38/0x48 [ 160.191941] vfs_ioctl+0x7c/0xb4 [ 160.195261] do_vfs_ioctl+0x9ec/0x2350 [ 160.199111] SyS_ioctl+0x6c/0xa4 [ 160.202436] INFO: Freed in kernfs_put+0x2c8/0x434 age=14 cpu=0 pid=7096 [ 160.209230] kernfs_put+0x2c8/0x434 [ 160.212825] kobject_del+0x50/0xcc [ 160.216332] cleanup_glue_dir+0x124/0x16c [ 160.220456] device_del+0x55c/0x5c8 [ 160.224047] __input_unregister_device+0x274/0x2a8 [ 160.228974] input_unregister_device+0x90/0xd0 [ 160.233553] uinput_destroy_device+0x15c/0x1dc [ 160.238131] uinput_release+0x44/0x5c [ 160.241898] __fput+0x1f4/0x4e4 [ 160.245127] ____fput+0x20/0x2c [ 160.248358] task_work_run+0x9c/0x174 [ 160.252127] do_notify_resume+0x104/0x6bc [ 160.256253] work_pending+0x8/0x14 [ 160.259751] INFO: Slab 0xffffffbf0215ff00 objects=33 used=11 fp=0xffffffc0857ffd08 flags=0x8101 [ 160.268693] INFO: Object 0xffffffc0857ffd08 @offset=15624 fp=0xffffffc0857fefb0 [ 160.268693] [ 160.277721] Redzone ffffffc0857ffd00: bb bb bb bb bb bb bb bb ........ [ 160.286656] Object ffffffc0857ffd08: 00 00 00 00 01 00 00 80 58 a2 37 45 c1 ff ff ff ........X.7E.... [ 160.296207] Object ffffffc0857ffd18: ae 21 10 0b 90 ff ff ff 20 fd 7f 85 c0 ff ff ff .!...... ....... [ 160.305780] Object ffffffc0857ffd28: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 160.315342] Object ffffffc0857ffd38: 00 00 00 00 00 00 00 00 7d a3 25 69 00 00 00 00 ........}.%i.... [ 160.324896] Object ffffffc0857ffd48: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 160.334446] Object ffffffc0857ffd58: 80 c0 28 47 c1 ff ff ff 00 00 00 00 00 00 00 00 ..(G............ [ 160.344000] Object ffffffc0857ffd68: 80 4a ce d1 c0 ff ff ff dc 32 01 00 01 00 00 00 .J.......2...... [ 160.353554] Object ffffffc0857ffd78: 11 00 ed 41 00 00 00 00 00 00 00 00 00 00 00 00 ...A............ [ 160.363099] Redzone ffffffc0857ffd88: bb bb bb bb bb bb bb bb ........ [ 160.372032] Padding ffffffc0857ffee0: 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZ [ 160.378299] CPU6: update max cpu_capacity 780 [ 160.380971] CPU: 4 PID: 7098 Comm: syz-executor Tainted: G S B W O 4.14.98+ #1 So, avoid the race by taking a udev lock inside `uinput_release()`. Change-Id: I3bbb07589b7b6e0e1b3bea572b5eb4f6b09774d6 Signed-off-by: Mukesh Ojha <mojha@codeaurora.org> Cc: Gaurav Kohli <gkohli@codeaurora.org> Cc: Peter Hutterer <peter.hutterer@who-t.net> Cc: Martin Kepplinger <martink@posteo.de> Cc: "Paul E. McKenney" <paulmck@linux.ibm.com> --- drivers/input/misc/uinput.c | 6 ++++++ 1 file changed, 6 insertions(+)