Description
In the Linux kernel, the following vulnerability has been resolved: comedi: multiq3: sanitize config options in multiq3_attach() Syzbot identified an issue [1] in multiq3_attach() that induces a task timeout due to open() or COMEDI_DEVCONFIG ioctl operations, specifically, in the case of multiq3 driver. This problem arose when syzkaller managed to craft weird configuration options used to specify the number of channels in encoder subdevice. If a particularly great number is passed to s->n_chan in multiq3_attach() via it->options[2], then multiple calls to multiq3_encoder_reset() at the end of driver-specific attach() method will be running for minutes, thus blocking tasks and affected devices as well. While this issue is most likely not too dangerous for real-life devices, it still makes sense to sanitize configuration inputs. Enable a sensible limit on the number of encoder chips (4 chips max, each with 2 channels) to stop this behaviour from manifesting. [1] Syzbot crash: INFO: task syz.2.19:6067 blocked for more than 143 seconds. ... Call Trace: <TASK> context_switch kernel/sched/core.c:5254 [inline] __schedule+0x17c4/0x4d60 kernel/sched/core.c:6862 __schedule_loop kernel/sched/core.c:6944 [inline] schedule+0x165/0x360 kernel/sched/core.c:6959 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7016 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 chrdev_open+0x4cc/0x5e0 fs/char_dev.c:414 do_dentry_open+0x953/0x13f0 fs/open.c:965 vfs_open+0x3b/0x340 fs/open.c:1097 ...
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
77e01cdbad5175f56027fd6fae00bd0fc175651a to < f9ff87aac7b37d462246c46d28912d382a8e2ea6affected77e01cdbad5175f56027fd6fae00bd0fc175651a to < 4cde9a7e025cc09b88097c70606f6b30c22880f4affected77e01cdbad5175f56027fd6fae00bd0fc175651a to < ad7ed3c9c7b8408e8612697bc43a5441fe386c71affected77e01cdbad5175f56027fd6fae00bd0fc175651a to < 049f14557450351750f929ebfff36d849511e132affected77e01cdbad5175f56027fd6fae00bd0fc175651a to < 8952bc1973cd54158c35e06bfb8c29ace7375a48affected77e01cdbad5175f56027fd6fae00bd0fc175651a to < 8dc2f02d3bada9247f00bfd2e5f61f68c389a0a3affected77e01cdbad5175f56027fd6fae00bd0fc175651a to < 543f4c380c2e1f35e60528df7cb54705cda7fee3affected77e01cdbad5175f56027fd6fae00bd0fc175651a to < f24c6e3a39fa355dabfb684c9ca82db579534e72affected
Linux Linux
Default version status: affected
2.6.30affected0 to < 2.6.30unaffected5.10.248 to ≤ 5.10.*unaffected5.15.198 to ≤ 5.15.*unaffected6.1.160 to ≤ 6.1.*unaffected6.6.120 to ≤ 6.6.*unaffected6.12.62 to ≤ 6.12.*unaffected6.17.12 to ≤ 6.17.*unaffected6.18.1 to ≤ 6.18.*unaffected6.19 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/f9ff87aac7b37d462246c46d28912d382a8e2ea6 ↗
- https://git.kernel.org/stable/c/4cde9a7e025cc09b88097c70606f6b30c22880f4 ↗
- https://git.kernel.org/stable/c/ad7ed3c9c7b8408e8612697bc43a5441fe386c71 ↗
- https://git.kernel.org/stable/c/049f14557450351750f929ebfff36d849511e132 ↗
- https://git.kernel.org/stable/c/8952bc1973cd54158c35e06bfb8c29ace7375a48 ↗
- https://git.kernel.org/stable/c/8dc2f02d3bada9247f00bfd2e5f61f68c389a0a3 ↗
- https://git.kernel.org/stable/c/543f4c380c2e1f35e60528df7cb54705cda7fee3 ↗
- https://git.kernel.org/stable/c/f24c6e3a39fa355dabfb684c9ca82db579534e72 ↗