https://github.com/torvalds/linux
Revision 6941051d3028963c3b0b3fcdd0815f2b51b957bb authored by Sudeep Holla on 18 October 2019, 10:58:15 UTC, committed by Rafael J. Wysocki on 22 October 2019, 16:07:30 UTC
Scheduled policy update work may end up racing with the freeing of the
policy and unregistering the driver.
One possible race is as below, where the cpufreq_driver is unregistered,
but the scheduled work gets executed at later stage when, cpufreq_driver
is NULL (i.e. after freeing the policy and driver).
Unable to handle kernel NULL pointer dereference at virtual address 0000001c
pgd = (ptrval)
[0000001c] *pgd=80000080204003, *pmd=00000000
Internal error: Oops: 206 [#1] SMP THUMB2
Modules linked in:
CPU: 0 PID: 34 Comm: kworker/0:1 Not tainted 5.4.0-rc3-00006-g67f5a8081a4b #86
Hardware name: ARM-Versatile Express
Workqueue: events handle_update
PC is at cpufreq_set_policy+0x58/0x228
LR is at dev_pm_qos_read_value+0x77/0xac
Control: 70c5387d Table: 80203000 DAC: fffffffd
Process kworker/0:1 (pid: 34, stack limit = 0x(ptrval))
(cpufreq_set_policy) from (refresh_frequency_limits.part.24+0x37/0x48)
(refresh_frequency_limits.part.24) from (handle_update+0x2f/0x38)
(handle_update) from (process_one_work+0x16d/0x3cc)
(process_one_work) from (worker_thread+0xff/0x414)
(worker_thread) from (kthread+0xff/0x100)
(kthread) from (ret_from_fork+0x11/0x28)
Fixes: 67d874c3b2c6 ("cpufreq: Register notifiers with the PM QoS framework")
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
[ rjw: Cancel the work before dropping the QoS requests ]
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
1 parent 2aac8bd
Tip revision: 6941051d3028963c3b0b3fcdd0815f2b51b957bb authored by Sudeep Holla on 18 October 2019, 10:58:15 UTC
cpufreq: Cancel policy update work scheduled before freeing
cpufreq: Cancel policy update work scheduled before freeing
Tip revision: 6941051
| File | Mode | Size |
|---|---|---|
| 9p | ||
| adfs | ||
| affs | ||
| afs | ||
| autofs | ||
| befs | ||
| bfs | ||
| btrfs | ||
| cachefiles | ||
| ceph | ||
| cifs | ||
| coda | ||
| configfs | ||
| cramfs | ||
| crypto | ||
| debugfs | ||
| devpts | ||
| dlm | ||
| ecryptfs | ||
| efivarfs | ||
| efs | ||
| erofs | ||
| exportfs | ||
| ext2 | ||
| ext4 | ||
| f2fs | ||
| fat | ||
| freevxfs | ||
| fscache | ||
| fuse | ||
| gfs2 | ||
| hfs | ||
| hfsplus | ||
| hostfs | ||
| hpfs | ||
| hugetlbfs | ||
| iomap | ||
| isofs | ||
| jbd2 | ||
| jffs2 | ||
| jfs | ||
| kernfs | ||
| lockd | ||
| minix | ||
| nfs | ||
| nfs_common | ||
| nfsd | ||
| nilfs2 | ||
| nls | ||
| notify | ||
| ntfs | ||
| ocfs2 | ||
| omfs | ||
| openpromfs | ||
| orangefs | ||
| overlayfs | ||
| proc | ||
| pstore | ||
| qnx4 | ||
| qnx6 | ||
| quota | ||
| ramfs | ||
| reiserfs | ||
| romfs | ||
| squashfs | ||
| sysfs | ||
| sysv | ||
| tracefs | ||
| ubifs | ||
| udf | ||
| ufs | ||
| unicode | ||
| verity | ||
| xfs | ||
| Kconfig | -rw-r--r-- | 7.6 KB |
| Kconfig.binfmt | -rw-r--r-- | 7.6 KB |
| Makefile | -rw-r--r-- | 4.4 KB |
| aio.c | -rw-r--r-- | 56.0 KB |
| anon_inodes.c | -rw-r--r-- | 4.6 KB |
| attr.c | -rw-r--r-- | 9.6 KB |
| bad_inode.c | -rw-r--r-- | 5.3 KB |
| binfmt_aout.c | -rw-r--r-- | 8.3 KB |
| binfmt_elf.c | -rw-r--r-- | 63.0 KB |
| binfmt_elf_fdpic.c | -rw-r--r-- | 47.1 KB |
| binfmt_em86.c | -rw-r--r-- | 2.8 KB |
| binfmt_flat.c | -rw-r--r-- | 28.0 KB |
| binfmt_misc.c | -rw-r--r-- | 18.5 KB |
| binfmt_script.c | -rw-r--r-- | 4.4 KB |
| block_dev.c | -rw-r--r-- | 55.9 KB |
| buffer.c | -rw-r--r-- | 90.2 KB |
| char_dev.c | -rw-r--r-- | 16.5 KB |
| compat.c | -rw-r--r-- | 3.2 KB |
| compat_binfmt_elf.c | -rw-r--r-- | 3.2 KB |
| compat_ioctl.c | -rw-r--r-- | 31.0 KB |
| coredump.c | -rw-r--r-- | 22.1 KB |
| d_path.c | -rw-r--r-- | 11.3 KB |
| dax.c | -rw-r--r-- | 45.8 KB |
| dcache.c | -rw-r--r-- | 83.9 KB |
| dcookies.c | -rw-r--r-- | 7.1 KB |
| direct-io.c | -rw-r--r-- | 40.8 KB |
| drop_caches.c | -rw-r--r-- | 1.8 KB |
| eventfd.c | -rw-r--r-- | 11.1 KB |
| eventpoll.c | -rw-r--r-- | 64.5 KB |
| exec.c | -rw-r--r-- | 46.9 KB |
| fcntl.c | -rw-r--r-- | 23.3 KB |
| fhandle.c | -rw-r--r-- | 6.8 KB |
| file.c | -rw-r--r-- | 24.2 KB |
| file_table.c | -rw-r--r-- | 10.2 KB |
| filesystems.c | -rw-r--r-- | 6.4 KB |
| fs-writeback.c | -rw-r--r-- | 74.4 KB |
| fs_context.c | -rw-r--r-- | 18.1 KB |
| fs_parser.c | -rw-r--r-- | 11.0 KB |
| fs_pin.c | -rw-r--r-- | 1.9 KB |
| fs_struct.c | -rw-r--r-- | 3.3 KB |
| fs_types.c | -rw-r--r-- | 2.5 KB |
| fsopen.c | -rw-r--r-- | 11.2 KB |
| inode.c | -rw-r--r-- | 60.7 KB |
| internal.h | -rw-r--r-- | 5.1 KB |
| io_uring.c | -rw-r--r-- | 95.1 KB |
| ioctl.c | -rw-r--r-- | 17.7 KB |
| libfs.c | -rw-r--r-- | 32.9 KB |
| locks.c | -rw-r--r-- | 78.9 KB |
| mbcache.c | -rw-r--r-- | 12.0 KB |
| mount.h | -rw-r--r-- | 4.0 KB |
| mpage.c | -rw-r--r-- | 21.1 KB |
| namei.c | -rw-r--r-- | 122.8 KB |
| namespace.c | -rw-r--r-- | 97.0 KB |
| no-block.c | -rw-r--r-- | 478 bytes |
| nsfs.c | -rw-r--r-- | 6.1 KB |
| open.c | -rw-r--r-- | 30.2 KB |
| pipe.c | -rw-r--r-- | 27.7 KB |
| pnode.c | -rw-r--r-- | 15.1 KB |
| pnode.h | -rw-r--r-- | 1.9 KB |
| posix_acl.c | -rw-r--r-- | 21.5 KB |
| proc_namespace.c | -rw-r--r-- | 7.8 KB |
| read_write.c | -rw-r--r-- | 51.6 KB |
| readdir.c | -rw-r--r-- | 13.3 KB |
| select.c | -rw-r--r-- | 34.2 KB |
| seq_file.c | -rw-r--r-- | 24.7 KB |
| signalfd.c | -rw-r--r-- | 9.0 KB |
| splice.c | -rw-r--r-- | 40.2 KB |
| stack.c | -rw-r--r-- | 2.5 KB |
| stat.c | -rw-r--r-- | 19.4 KB |
| statfs.c | -rw-r--r-- | 9.6 KB |
| super.c | -rw-r--r-- | 47.9 KB |
| sync.c | -rw-r--r-- | 10.4 KB |
| timerfd.c | -rw-r--r-- | 13.5 KB |
| userfaultfd.c | -rw-r--r-- | 51.2 KB |
| utimes.c | -rw-r--r-- | 7.3 KB |
| xattr.c | -rw-r--r-- | 23.5 KB |
Computing file changes ...
