Description
In the Linux kernel, the following vulnerability has been resolved: ipv6: prevent in6_dev_get() from resurrecting inet6_dev in6_dev_get() reads dev->ip6_ptr under RCU and then unconditionally increments its refcount. Device teardown can clear the pointer and drop the last reference between these operations. The increment then resurrects an object whose RCU free has already been queued, so callers can use it after it is freed. Use refcount_inc_not_zero() and return NULL when the object has already reached zero. RCU keeps the memory accessible through the attempted reference acquisition, and a successful increment pins the object for the caller. An independent run on the exact unpatched 6f5156d7a31a (v7.2-rc3) kernel reproduced the invalid reference acquisition as UID 1000: refcount_t: addition on 0; use-after-free. ip6_mc_source+0xef4/0x17e0 It was followed by the corresponding reference underflow in ip6_mc_source(). The supplied trace from the same unpatched revision additionally shows the access after the RCU read-side section ends: BUG: KASAN: slab-use-after-free in mutex_lock+0x76/0xe0 Write of size 8 at addr ffff888015b50240 by task poc/1219 Bug found and triaged by OpenAI Security Research and validated by Trail of Bits.
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
8814c4b533817df825485ff32ce6ac406c3a54d1 to < 785d908f8d21c8bc78b6fb2c2932ab662bf6918aaffected8814c4b533817df825485ff32ce6ac406c3a54d1 to < aedcfefdb5b7ed7f8a6196a3e68a25bdbe51d2f8affected8814c4b533817df825485ff32ce6ac406c3a54d1 to < 145812b678de9f3b59780173be3c0d22ed60dd93affected8814c4b533817df825485ff32ce6ac406c3a54d1 to < cc5bd568f9b7683e60841b6fd02c10d64535bd6eaffected8814c4b533817df825485ff32ce6ac406c3a54d1 to < 1c206d461c680c3151daa3c89fc26eaf5bf98a7faffected8814c4b533817df825485ff32ce6ac406c3a54d1 to < 680fbd7942185448eadb990a3d10a53eb946b702affected8814c4b533817df825485ff32ce6ac406c3a54d1 to < 14e812ab41df0cac033479da835ec9a5de633404affected8814c4b533817df825485ff32ce6ac406c3a54d1 to < 0e243671bc7b8eaf00f83dd2f4367436dc0cff98affected
Linux Linux
Default version status: affected
2.6.19affected0 to < 2.6.19unaffected5.10.265 to ≤ 5.10.*unaffected5.15.216 to ≤ 5.15.*unaffected6.1.183 to ≤ 6.1.*unaffected6.6.152 to ≤ 6.6.*unaffected6.12.104 to ≤ 6.12.*unaffected6.18.45 to ≤ 6.18.*unaffected7.1.9 to ≤ 7.1.*unaffected7.2 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/785d908f8d21c8bc78b6fb2c2932ab662bf6918a ↗
- https://git.kernel.org/stable/c/aedcfefdb5b7ed7f8a6196a3e68a25bdbe51d2f8 ↗
- https://git.kernel.org/stable/c/145812b678de9f3b59780173be3c0d22ed60dd93 ↗
- https://git.kernel.org/stable/c/cc5bd568f9b7683e60841b6fd02c10d64535bd6e ↗
- https://git.kernel.org/stable/c/1c206d461c680c3151daa3c89fc26eaf5bf98a7f ↗
- https://git.kernel.org/stable/c/680fbd7942185448eadb990a3d10a53eb946b702 ↗
- https://git.kernel.org/stable/c/14e812ab41df0cac033479da835ec9a5de633404 ↗
- https://git.kernel.org/stable/c/0e243671bc7b8eaf00f83dd2f4367436dc0cff98 ↗