Hosts the 0x221E linux distro kernel. https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-5.4.y 2020-08-19T06:16:24Z 2020-08-19T06:16:24Z Tuomas Tynkkynen 2020-06-21T11:30:40Z urn:sha1:86f95b631490b5530d5f4e3e3d1b43fe900574a7 commit e30cc79cc80fd919b697a15c5000d9f57487de8e upstream. Syzbot reports a NULL-ptr deref in the kref_put() call: BUG: KASAN: null-ptr-deref in media_request_put drivers/media/mc/mc-request.c:81 [inline] kref_put include/linux/kref.h:64 [inline] media_request_put drivers/media/mc/mc-request.c:81 [inline] media_request_close+0x4d/0x170 drivers/media/mc/mc-request.c:89 __fput+0x2ed/0x750 fs/file_table.c:281 task_work_run+0x147/0x1d0 kernel/task_work.c:123 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop arch/x86/entry/common.c:165 [inline] prepare_exit_to_usermode+0x48e/0x600 arch/x86/entry/common.c:196 What led to this crash was an injected memory allocation failure in media_request_alloc(): FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 should_failslab+0x5/0x20 kmem_cache_alloc_trace+0x57/0x300 ? anon_inode_getfile+0xe5/0x170 media_request_alloc+0x339/0x440 media_device_request_alloc+0x94/0xc0 media_device_ioctl+0x1fb/0x330 ? do_vfs_ioctl+0x6ea/0x1a00 ? media_ioctl+0x101/0x120 ? __media_device_usb_init+0x430/0x430 ? media_poll+0x110/0x110 __se_sys_ioctl+0xf9/0x160 do_syscall_64+0xf3/0x1b0 When that allocation fails, filp->private_data is left uninitialized which media_request_close() does not expect and crashes. To avoid this, reorder media_request_alloc() such that allocating the struct file happens as the last step thus media_request_close() will no longer get called for a partially created media request. Reported-by: syzbot+6bed2d543cf7e48b822b@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi> Fixes: 10905d70d788 ("media: media-request: implement media requests") Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 2019-05-28T16:15:46Z Hans Verkuil 2019-05-02T13:42:31Z urn:sha1:c612e54fca55d9380c1378eaa623d74ed89b62db It is really weird that the media controller sources are all top-level in drivers/media. It is a bit of a left-over from long ago when most media sources were all at the top-level. At some point we reorganized the directory structure, but the media-*.c sources where never moved to their own directory. So create a new mc directory and move all sources there. Also rename the prefix from media- to mc-. Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>