Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: ipv4: igmp: Fix potential memory leaks in igmp_mod_timer() and igmp_stop_timer() When a timer is deleted and not re-armed in igmp_mod_timer(), or stopped in igmp_stop_timer(), the code currently decrements the reference counter of the multicast list entry @im using refcount_dec(&im->refcnt). However, both functions can be called from the RCU reader path: - igmp_mod_timer() via igmp_heard_query() -> for_each_pmc_rcu() - igmp_stop_timer() via igmp_rcv() -> igmp_heard_report() If the group im was concurrently removed from the list by ip_mc_dec_group(), its reference count might have already been decremented to 1. In this case, timer_delete() succeeds, and refcount_dec() decrements the refcount from 1 to 0. Since refcount_dec() does not free the object when it hits 0 (unlike ip_ma_put()), the im structure is leaked. Fix this by using ip_ma_put(im) instead of refcount_dec(&im->refcnt), and deferring the put until after the spinlock is released.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 2d0effadf8d2cc9d006e4c4ab0ab6737aed28d77; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 40d6360ccf9bcbe17b5cb248a84e8e004aac2faa; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before f60ec3058a85447008b88b762c859d336163acb3; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 95128dc74425ec19ed4f2077ccc651e791ff4b75; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 3546deaa0c30a14c7cdb5dc8f2432cb428f0cd36 |
| Linux / Linux | affected 2.6.12; unaffected 0 before 2.6.12; unaffected 6.6.160 through 6.6.*; unaffected 6.12.114 through 6.12.*; unaffected 6.18.40 through 6.18.*; unaffected 7.1.5 through 7.1.*; unaffected 7.2 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/2d0effadf8d2cc9d006e4c4ab0ab6737aed28d77
- https://git.kernel.org/stable/c/40d6360ccf9bcbe17b5cb248a84e8e004aac2faa
- https://git.kernel.org/stable/c/f60ec3058a85447008b88b762c859d336163acb3
- https://git.kernel.org/stable/c/95128dc74425ec19ed4f2077ccc651e791ff4b75
- https://git.kernel.org/stable/c/3546deaa0c30a14c7cdb5dc8f2432cb428f0cd36