# tracer: nop
#
# entries-in-buffer/entries-written: 3/3 #P:16
#
# _-----=> irqs-off
# / _----=> need-resched
# |/ _-----=> need-resched_lazy
# || / _---=> hardirq/softirq
# ||| / _--=> preempt-depth
# |||| / _-=> preempt-lazy-depth
# ||||| / _-=> migrate-disable
# |||||| / delay
# TASK-PID CPU# ||||||| TIMESTAMP FUNCTION
# | | | ||||||| | |
automount-5999 [001] ....... 170.320000: 0:
copy_mount_options(): copy 0xd017d560b000 data 0xc2dfffffe340 size
0x1000 USER_DS 0xc2dffffff000 TASK_SIZE 0xd00000000000
automount-5999 [001] ....... 170.320000: :
exact_copy_from_user(): !access_ok
automount-5999 [001] ....... 170.320000: :
copy_mount_options(): return -EFAULT
On 15.10.2019 21:40, Al Viro wrote:
On Tue, Oct 15, 2019 at 09:09:02PM +0300, Pavel V. Panteleev wrote:
Hello,
copy_mount_options() checks that data doesn't cross TASK_SIZE boundary. It's
not correct. Really it should check USER_DS boudary, because some archs have
TASK_SIZE not equal to USER_DS. In this case (USER_DS != TASK_SIZE)
exact_copy_from_user() will stop on access_ok() check, if data cross
USER_DS, but doesn't cross TASK_SIZE.
Details of the call chain, please.
