{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2023-53823","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2025-12-09T01:27:17.824Z","datePublished":"2025-12-09T01:29:36.343Z","dateUpdated":"2026-05-11T19:52:13.464Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-05-11T19:52:13.464Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nblock/rq_qos: protect rq_qos apis with a new lock\n\ncommit 50e34d78815e (\"block: disable the elevator int del_gendisk\")\nmove rq_qos_exit() from disk_release() to del_gendisk(), this will\nintroduce some problems:\n\n1) If rq_qos_add() is triggered by enabling iocost/iolatency through\n   cgroupfs, then it can concurrent with del_gendisk(), it's not safe to\n   write 'q->rq_qos' concurrently.\n\n2) Activate cgroup policy that is relied on rq_qos will call\n   rq_qos_add() and blkcg_activate_policy(), and if rq_qos_exit() is\n   called in the middle, null-ptr-dereference will be triggered in\n   blkcg_activate_policy().\n\n3) blkg_conf_open_bdev() can call blkdev_get_no_open() first to find the\n   disk, then if rq_qos_exit() from del_gendisk() is done before\n   rq_qos_add(), then memory will be leaked.\n\nThis patch add a new disk level mutex 'rq_qos_mutex':\n\n1) The lock will protect rq_qos_exit() directly.\n\n2) For wbt that doesn't relied on blk-cgroup, rq_qos_add() can only be\n   called from disk initialization for now because wbt can't be\n   destructed until rq_qos_exit(), so it's safe not to protect wbt for\n   now. Hoever, in case that rq_qos dynamically destruction is supported\n   in the furture, this patch also protect rq_qos_add() from wbt_init()\n   directly, this is enough because blk-sysfs already synchronize\n   writers with disk removal.\n\n3) For iocost and iolatency, in order to synchronize disk removal and\n   cgroup configuration, the lock is held after blkdev_get_no_open()\n   from blkg_conf_open_bdev(), and is released in blkg_conf_exit().\n   In order to fix the above memory leak, disk_live() is checked after\n   holding the new lock."}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["block/blk-cgroup.c","block/blk-core.c","block/blk-rq-qos.c","block/blk-wbt.c","include/linux/blkdev.h"],"versions":[{"version":"50e34d78815e474d410f342fbe783b18192ca518","lessThan":"16398b4638b5cd8c1dc95fc940a1591a801d53ce","status":"affected","versionType":"git"},{"version":"50e34d78815e474d410f342fbe783b18192ca518","lessThan":"a13bd91be22318768d55470cbc0b0f4488ef9edf","status":"affected","versionType":"git"},{"version":"f28699fafc047ec33299da01e928c3a0073c5cc6","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["block/blk-cgroup.c","block/blk-core.c","block/blk-rq-qos.c","block/blk-wbt.c","include/linux/blkdev.h"],"versions":[{"version":"5.19","status":"affected"},{"version":"0","lessThan":"5.19","status":"unaffected","versionType":"semver"},{"version":"6.4.4","lessThanOrEqual":"6.4.*","status":"unaffected","versionType":"semver"},{"version":"6.5","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.19","versionEndExcluding":"6.4.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.19","versionEndExcluding":"6.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.18.8"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/16398b4638b5cd8c1dc95fc940a1591a801d53ce"},{"url":"https://git.kernel.org/stable/c/a13bd91be22318768d55470cbc0b0f4488ef9edf"}],"title":"block/rq_qos: protect rq_qos apis with a new lock","x_generator":{"engine":"bippy-1.2.0"}}}}