{"id":"CVE-2026-90185","published":"2026-09-17T17:17:12.980","lastModified":"2026-09-17T17:17:12.980","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnull_blk: serialize configfs attribute stores with the lock\n\nThe NULLB_DEVICE_ATTR _store takes no lock: apply_fn attributes\n(submit_queues, poll_queues) get dev->NAME written again after apply_fn\nreturns, outside its lock; APPLY=NULL attributes are entirely lockless.\nconfigfs only serializes stores per-open-file, so concurrent stores on\nseparate fds race.\n\nFor apply_fn attributes, once one store's apply_fn has reconfigured the\nhardware, a second (losing) store can still overwrite dev->NAME\nafterwards. This leaves dev->submit_queues out of sync with the live\nqueue count, which is later caught by the WARN_ON_ONCE() in\nnull_map_queues().\n\nFor !apply_fn attributes, power_store()'s null_add_dev() validates and\nbuilds the device under \"lock\" but only sets CONFIGURED afterwards. A store\nslipping in during this window can change a field mid-setup -- for example,\nzone_nr_conv can be pushed above nr_zones after it has already been\nclamped, leading to an out-of-bounds dev->zones[] access.\n\nTake \"lock\" in the macro around the apply_fn call, the CONFIGURED test and\nthe field write, and move it out of nullb_apply_submit_queues()/\nnullb_apply_poll_queues() so both paths are covered once. This serializes\nstores with power_store's setup and with each other.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/3945ce8cbce4e328e6fdf0b522dc71e340de19db","tags":[]},{"url":"https://git.kernel.org/stable/c/65cae82fd3c39b53430672cb9e3ecd267471a6ce","tags":[]},{"url":"https://git.kernel.org/stable/c/7e7fff51808237703a3a1df6dd5cae1dfd1db86d","tags":[]},{"url":"https://git.kernel.org/stable/c/88d806d0e1d36246208386a8e55b511c1b3d647c","tags":[]},{"url":"https://git.kernel.org/stable/c/8e839ed5210399a0330a8a6c5885c1d40a537c6d","tags":[]},{"url":"https://git.kernel.org/stable/c/c70994c2862b05e44728912b2ea9487d31e2aea7","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}