Description
In the Linux kernel, the following vulnerability has been resolved: HID: uclogic: fix use-after-free of inrange_timer on remove uclogic_remove() cancels the pen in-range timer and then stops the device: timer_delete_sync(&drvdata->inrange_timer); hid_hw_stop(hdev); timer_delete_sync() only guarantees the timer is idle at that instant. uclogic_raw_event_pen() keeps delivering pen reports until hid_hw_stop() stops the transport several lines later, and every report with pen->inrange == UCLOGIC_PARAMS_PEN_INRANGE_NONE re-arms the timer: mod_timer(&drvdata->inrange_timer, jiffies + msecs_to_jiffies(100)); A report landing between the timer_delete_sync() call and the transport teardown in hid_hw_stop() re-arms inrange_timer after it was cancelled. uclogic_remove() then returns and the devm drvdata is freed, while hid_hw_stop() has already freed the input device drvdata->pen_input points at, so when the timer fires ~100 ms later uclogic_inrange_timeout() dereferences freed memory -- a use-after-free in timer-softirq context. Swapping the two calls is not a fix: stopping the device first frees drvdata->pen_input via hidinput_disconnect() while the timer may still be pending, so a timer already armed before removal fires on the freed input device in the window before timer_delete_sync() runs. Use timer_shutdown_sync() before hid_hw_stop() instead. It cancels the timer, waits for a running callback while pen_input is still valid, and prevents any further re-arming -- a later mod_timer() from an in-flight report is silently ignored -- so the timer is provably dead before hid_hw_stop() frees the inputs. This is the ordering the timer core documents for this "timer re-armed from another path" teardown case.
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
01309e29eb95c16bd48984f2589fad0cbf5e27d1 to < f40243358b407aec362fe305fabfcdc94a3abd89affected01309e29eb95c16bd48984f2589fad0cbf5e27d1 to < dc5108f18f58870a8dd4203a02a47e571a2be7f0affected01309e29eb95c16bd48984f2589fad0cbf5e27d1 to < 9d77ac82e57ead056cf3f71d347083ed9244ad90affected01309e29eb95c16bd48984f2589fad0cbf5e27d1 to < e750cdb6de009aace3c77f37fe2173f96175e8e4affected01309e29eb95c16bd48984f2589fad0cbf5e27d1 to < 849e537160bbb77fe419ecc3944bfe125dcd441baffected01309e29eb95c16bd48984f2589fad0cbf5e27d1 to < f1b3ca06380531f49f988f4721d3ed30b0d7a5d2affected01309e29eb95c16bd48984f2589fad0cbf5e27d1 to < f13d0a00204b05e62336da0ab72ea0d87b56690caffected01309e29eb95c16bd48984f2589fad0cbf5e27d1 to < 506fd50a9027340f0e9dcc587d10ccb03312dba6affected
Linux Linux
Default version status: affected
5.1affected0 to < 5.1unaffected5.15.220 to ≤ 5.15.*unaffected6.1.187 to ≤ 6.1.*unaffected6.6.156 to ≤ 6.6.*unaffected6.12.108 to ≤ 6.12.*unaffected6.18.47 to ≤ 6.18.*unaffected7.1.11 to ≤ 7.1.*unaffected7.2.1 to ≤ 7.2.*unaffected7.3 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/f40243358b407aec362fe305fabfcdc94a3abd89 ↗
- https://git.kernel.org/stable/c/dc5108f18f58870a8dd4203a02a47e571a2be7f0 ↗
- https://git.kernel.org/stable/c/9d77ac82e57ead056cf3f71d347083ed9244ad90 ↗
- https://git.kernel.org/stable/c/e750cdb6de009aace3c77f37fe2173f96175e8e4 ↗
- https://git.kernel.org/stable/c/849e537160bbb77fe419ecc3944bfe125dcd441b ↗
- https://git.kernel.org/stable/c/f1b3ca06380531f49f988f4721d3ed30b0d7a5d2 ↗
- https://git.kernel.org/stable/c/f13d0a00204b05e62336da0ab72ea0d87b56690c ↗
- https://git.kernel.org/stable/c/506fd50a9027340f0e9dcc587d10ccb03312dba6 ↗