interconnect: Fix use after free in icc_get() and of_icc_get_by_index()

Overview

In the Linux kernel, the following vulnerability has been resolved:

interconnect: Fix use after free in icc_get() and of_icc_get_by_index()

In of_icc_get_by_index() and icc_get(), if the dynamic allocation for path->name fails via kasprintf(), the error handling path directly calls kfree(path) to free the path object and returns an error.

However, prior to this point, path_find() calls path_init(), which already links the path's requests into the req_list of the respective interconnect nodes via hlist_add_head(). Directly invoking kfree(path) leaves dangling pointers in the hlist. A subsequent call to icc_get() or icc_set_bw() will traverse or modify these corrupted lists, triggering a slab use afterfree.

KASAN report showing the vulnerability when reproducing via debugfs:

BUG: KASAN: slab-use-after-free in path_find+0x6f8/0xcfc Write of size 8 at addr fff000000d43f748 by task sh/1 ... Call trace: kasan_report+0xac/0xfc path_find+0x6f8/0xcfc icc_get+0x148/0x380 icc_get_set+0xf8/0x2d0 ... Freed by task 1: kfree+0x1a0/0x4a4 icc_get+0x2cc/0x380 icc_get_set+0xf8/0x2d0

Fix this by replacing kfree(path) with the proper teardown function, icc_put(path), which safely removes the requests from the req_list using hlist_del() and drops the provider usage references before freeing the memory.

Additionally, in icc_get(), ensure that the icc_lock mutex is released prior to calling icc_put(path) to avoid a deadlock, as icc_put() internally acquires the same lock.

Affected

• Linux >= 3791163602f7140011a8dc1691cfe6ec0cb1ef07 < 03c3af594dea9196cf6ca70d914b42aa8c873c35
• Linux >= 3791163602f7140011a8dc1691cfe6ec0cb1ef07 < d4d73decdb9a44a248b1cbd04ed6f334df544d9c
• Linux >= 3791163602f7140011a8dc1691cfe6ec0cb1ef07 < 9a671125d4228357e5b929733c4593d27a273749
• Linux >= 3791163602f7140011a8dc1691cfe6ec0cb1ef07 < fedea72e8f312fe7d0c6cb19353e61d2d5643b11
• Linux >= 3791163602f7140011a8dc1691cfe6ec0cb1ef07 < a4e9aa7907ade87d1d96853d14e05dcf682f8363
• Linux >= 3791163602f7140011a8dc1691cfe6ec0cb1ef07 < db8147c5d5ad2cfa21c2be566f95981b41b05de6
• Linux >= 3791163602f7140011a8dc1691cfe6ec0cb1ef07 < d715d19cfcfe99f361adb05cefc143a95d400b87
• Linux >= 3791163602f7140011a8dc1691cfe6ec0cb1ef07 < 25c7e242aca084fdc1098248194032317dca625d
• Linux 5.6

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

Vendor advisories

• Red Hat VEX · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-14 · vex