{"dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": {"cveId": "CVE-2024-47706", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-09-30T16:00:12.946Z", "datePublished": "2024-10-21T11:53:40.759Z", "dateUpdated": "2024-11-08T15:56:22.679Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2024-11-08T15:56:22.679Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nblock, bfq: fix possible UAF for bfqq->bic with merge chain\n\n1) initial state, three tasks:\n\n\t\tProcess 1 Process 2\tProcess 3\n\t\t (BIC1) (BIC2)\t\t (BIC3)\n\t\t | \u039b | \u039b\t\t | \u039b\n\t\t | | | |\t\t | |\n\t\t V | V |\t\t V |\n\t\t bfqq1 bfqq2\t\t bfqq3\nprocess ref:\t 1\t\t 1\t\t 1\n\n2) bfqq1 merged to bfqq2:\n\n\t\tProcess 1 Process 2\tProcess 3\n\t\t (BIC1) (BIC2)\t\t (BIC3)\n\t\t | |\t\t | \u039b\n\t\t \\--------------\\|\t\t | |\n\t\t V\t\t V |\n\t\t bfqq1--------->bfqq2\t\t bfqq3\nprocess ref:\t 0\t\t 2\t\t 1\n\n3) bfqq2 merged to bfqq3:\n\n\t\tProcess 1 Process 2\tProcess 3\n\t\t (BIC1) (BIC2)\t\t (BIC3)\n\t here -> \u039b |\t\t |\n\t\t \\--------------\\ \\-------------\\|\n\t\t V\t\t V\n\t\t bfqq1--------->bfqq2---------->bfqq3\nprocess ref:\t 0\t\t 1\t\t 3\n\nIn this case, IO from Process 1 will get bfqq2 from BIC1 first, and then\nget bfqq3 through merge chain, and finially handle IO by bfqq3.\nHowerver, current code will think bfqq2 is owned by BIC1, like initial\nstate, and set bfqq2->bic to BIC1.\n\nbfq_insert_request\n-> by Process 1\n bfqq = bfq_init_rq(rq)\n bfqq = bfq_get_bfqq_handle_split\n bfqq = bic_to_bfqq\n -> get bfqq2 from BIC1\n bfqq->ref++\n rq->elv.priv[0] = bic\n rq->elv.priv[1] = bfqq\n if (bfqq_process_refs(bfqq) == 1)\n bfqq->bic = bic\n -> record BIC1 to bfqq2\n\n __bfq_insert_request\n new_bfqq = bfq_setup_cooperator\n -> get bfqq3 from bfqq2->new_bfqq\n bfqq_request_freed(bfqq)\n new_bfqq->ref++\n rq->elv.priv[1] = new_bfqq\n -> handle IO by bfqq3\n\nFix the problem by checking bfqq is from merge chain fist. And this\nmight fix a following problem reported by our syzkaller(unreproducible):\n\n==================================================================\nBUG: KASAN: slab-use-after-free in bfq_do_early_stable_merge block/bfq-iosched.c:5692 [inline]\nBUG: KASAN: slab-use-after-free in bfq_do_or_sched_stable_merge block/bfq-iosched.c:5805 [inline]\nBUG: KASAN: slab-use-after-free in bfq_get_queue+0x25b0/0x2610 block/bfq-iosched.c:5889\nWrite of size 1 at addr ffff888123839eb8 by task kworker/0:1H/18595\n\nCPU: 0 PID: 18595 Comm: kworker/0:1H Tainted: G L 6.6.0-07439-gba2303cacfda #6\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014\nWorkqueue: kblockd blk_mq_requeue_work\nCall Trace:\n <TASK>\n __dump_stack lib/dump_stack.c:88 [inline]\n dump_stack_lvl+0x91/0xf0 lib/dump_stack.c:106\n print_address_description mm/kasan/report.c:364 [inline]\n print_report+0x10d/0x610 mm/kasan/report.c:475\n kasan_report+0x8e/0xc0 mm/kasan/report.c:588\n bfq_do_early_stable_merge block/bfq-iosched.c:5692 [inline]\n bfq_do_or_sched_stable_merge block/bfq-iosched.c:5805 [inline]\n bfq_get_queue+0x25b0/0x2610 block/bfq-iosched.c:5889\n bfq_get_bfqq_handle_split+0x169/0x5d0 block/bfq-iosched.c:6757\n bfq_init_rq block/bfq-iosched.c:6876 [inline]\n bfq_insert_request block/bfq-iosched.c:6254 [inline]\n bfq_insert_requests+0x1112/0x5cf0 block/bfq-iosched.c:6304\n blk_mq_insert_request+0x290/0x8d0 block/blk-mq.c:2593\n blk_mq_requeue_work+0x6bc/0xa70 block/blk-mq.c:1502\n process_one_work kernel/workqueue.c:2627 [inline]\n process_scheduled_works+0x432/0x13f0 kernel/workqueue.c:2700\n worker_thread+0x6f2/0x1160 kernel/workqueue.c:2781\n kthread+0x33c/0x440 kernel/kthread.c:388\n ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147\n ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:305\n </TASK>\n\nAllocated by task 20776:\n kasan_save_stack+0x20/0x40 mm/kasan/common.c:45\n kasan_set_track+0x25/0x30 mm/kasan/common.c:52\n __kasan_slab_alloc+0x87/0x90 mm/kasan/common.c:328\n kasan_slab_alloc include/linux/kasan.h:188 [inline]\n slab_post_alloc_hook mm/slab.h:763 [inline]\n slab_alloc_node mm/slub.c:3458 [inline]\n kmem_cache_alloc_node+0x1a4/0x6f0 mm/slub.c:3503\n ioc_create_icq block/blk-ioc.c:370 [inline]\n---truncated---"}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["block/bfq-iosched.c"], "versions": [{"version": "36eca8948323", "lessThan": "a9bdd5b36887", "status": "affected", "versionType": "git"}, {"version": "36eca8948323", "lessThan": "bc2140534b2a", "status": "affected", "versionType": "git"}, {"version": "36eca8948323", "lessThan": "e1277ae780cc", "status": "affected", "versionType": "git"}, {"version": "36eca8948323", "lessThan": "8aa9de02a4be", "status": "affected", "versionType": "git"}, {"version": "36eca8948323", "lessThan": "ddbdaad12325", "status": "affected", "versionType": "git"}, {"version": "36eca8948323", "lessThan": "7faed2896d78", "status": "affected", "versionType": "git"}, {"version": "36eca8948323", "lessThan": "880692ee233b", "status": "affected", "versionType": "git"}, {"version": "36eca8948323", "lessThan": "6d130db286ad", "status": "affected", "versionType": "git"}, {"version": "36eca8948323", "lessThan": "18ad4df091dd", "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/bfq-iosched.c"], "versions": [{"version": "4.12", "status": "affected"}, {"version": "0", "lessThan": "4.12", "status": "unaffected", "versionType": "semver"}, {"version": "4.19.323", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.4.285", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.227", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.168", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.113", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.54", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.10.13", "lessThanOrEqual": "6.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.11.2", "lessThanOrEqual": "6.11.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12-rc1", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "references": [{"url": "https://git.kernel.org/stable/c/a9bdd5b36887d2bacb8bc777fd18317c99fc2587"}, {"url": "https://git.kernel.org/stable/c/bc2140534b2aae752e4f7cb4489642dbb5ec4777"}, {"url": "https://git.kernel.org/stable/c/e1277ae780cca4e69ef5468d4582dfd48f0b8320"}, {"url": "https://git.kernel.org/stable/c/8aa9de02a4be2e7006e636816ce19b0d667ceaa3"}, {"url": "https://git.kernel.org/stable/c/ddbdaad123254fb53e32480cb74a486a6868b1e0"}, {"url": "https://git.kernel.org/stable/c/7faed2896d78e48ec96229e73b30b0af6c00a9aa"}, {"url": "https://git.kernel.org/stable/c/880692ee233ba63808182705b3333403413b58f5"}, {"url": "https://git.kernel.org/stable/c/6d130db286ad0ea392c96ebb2551acf0d7308048"}, {"url": "https://git.kernel.org/stable/c/18ad4df091dd5d067d2faa8fce1180b79f7041a7"}], "title": "block, bfq: fix possible UAF for bfqq->bic with merge chain", "x_generator": {"engine": "bippy-9e1c9544281a"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2024-47706", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2024-10-21T13:03:53.838190Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-10-21T13:04:19.673Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2024-47706", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2024-10-21T13:03:53.838190Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-10-21T13:03:56.861Z"}}], "cna": {"title": "block, bfq: fix possible UAF for bfqq->bic with merge chain", "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "36eca8948323", "lessThan": "a9bdd5b36887", "versionType": "git"}, {"status": "affected", "version": "36eca8948323", "lessThan": "bc2140534b2a", "versionType": "git"}, {"status": "affected", "version": "36eca8948323", "lessThan": "e1277ae780cc", "versionType": "git"}, {"status": "affected", "version": "36eca8948323", "lessThan": "8aa9de02a4be", "versionType": "git"}, {"status": "affected", "version": "36eca8948323", "lessThan": "ddbdaad12325", "versionType": "git"}, {"status": "affected", "version": "36eca8948323", "lessThan": "7faed2896d78", "versionType": "git"}, {"status": "affected", "version": "36eca8948323", "lessThan": "880692ee233b", "versionType": "git"}, {"status": "affected", "version": "36eca8948323", "lessThan": "6d130db286ad", "versionType": "git"}, {"status": "affected", "version": "36eca8948323", "lessThan": "18ad4df091dd", "versionType": "git"}], "programFiles": ["block/bfq-iosched.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "4.12"}, {"status": "unaffected", "version": "0", "lessThan": "4.12", "versionType": "semver"}, {"status": "unaffected", "version": "4.19.323", "versionType": "semver", "lessThanOrEqual": "4.19.*"}, {"status": "unaffected", "version": "5.4.285", "versionType": "semver", "lessThanOrEqual": "5.4.*"}, {"status": "unaffected", "version": "5.10.227", "versionType": "semver", "lessThanOrEqual": "5.10.*"}, {"status": "unaffected", "version": "5.15.168", "versionType": "semver", "lessThanOrEqual": "5.15.*"}, {"status": "unaffected", "version": "6.1.113", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.54", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.10.13", "versionType": "semver", "lessThanOrEqual": "6.10.*"}, {"status": "unaffected", "version": "6.11.2", "versionType": "semver", "lessThanOrEqual": "6.11.*"}, {"status": "unaffected", "version": "6.12-rc1", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["block/bfq-iosched.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/a9bdd5b36887d2bacb8bc777fd18317c99fc2587"}, {"url": "https://git.kernel.org/stable/c/bc2140534b2aae752e4f7cb4489642dbb5ec4777"}, {"url": "https://git.kernel.org/stable/c/e1277ae780cca4e69ef5468d4582dfd48f0b8320"}, {"url": "https://git.kernel.org/stable/c/8aa9de02a4be2e7006e636816ce19b0d667ceaa3"}, {"url": "https://git.kernel.org/stable/c/ddbdaad123254fb53e32480cb74a486a6868b1e0"}, {"url": "https://git.kernel.org/stable/c/7faed2896d78e48ec96229e73b30b0af6c00a9aa"}, {"url": "https://git.kernel.org/stable/c/880692ee233ba63808182705b3333403413b58f5"}, {"url": "https://git.kernel.org/stable/c/6d130db286ad0ea392c96ebb2551acf0d7308048"}, {"url": "https://git.kernel.org/stable/c/18ad4df091dd5d067d2faa8fce1180b79f7041a7"}], "x_generator": {"engine": "bippy-9e1c9544281a"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nblock, bfq: fix possible UAF for bfqq->bic with merge chain\n\n1) initial state, three tasks:\n\n\t\tProcess 1 Process 2\tProcess 3\n\t\t (BIC1) (BIC2)\t\t (BIC3)\n\t\t | \u039b | \u039b\t\t | \u039b\n\t\t | | | |\t\t | |\n\t\t V | V |\t\t V |\n\t\t bfqq1 bfqq2\t\t bfqq3\nprocess ref:\t 1\t\t 1\t\t 1\n\n2) bfqq1 merged to bfqq2:\n\n\t\tProcess 1 Process 2\tProcess 3\n\t\t (BIC1) (BIC2)\t\t (BIC3)\n\t\t | |\t\t | \u039b\n\t\t \\--------------\\|\t\t | |\n\t\t V\t\t V |\n\t\t bfqq1--------->bfqq2\t\t bfqq3\nprocess ref:\t 0\t\t 2\t\t 1\n\n3) bfqq2 merged to bfqq3:\n\n\t\tProcess 1 Process 2\tProcess 3\n\t\t (BIC1) (BIC2)\t\t (BIC3)\n\t here -> \u039b |\t\t |\n\t\t \\--------------\\ \\-------------\\|\n\t\t V\t\t V\n\t\t bfqq1--------->bfqq2---------->bfqq3\nprocess ref:\t 0\t\t 1\t\t 3\n\nIn this case, IO from Process 1 will get bfqq2 from BIC1 first, and then\nget bfqq3 through merge chain, and finially handle IO by bfqq3.\nHowerver, current code will think bfqq2 is owned by BIC1, like initial\nstate, and set bfqq2->bic to BIC1.\n\nbfq_insert_request\n-> by Process 1\n bfqq = bfq_init_rq(rq)\n bfqq = bfq_get_bfqq_handle_split\n bfqq = bic_to_bfqq\n -> get bfqq2 from BIC1\n bfqq->ref++\n rq->elv.priv[0] = bic\n rq->elv.priv[1] = bfqq\n if (bfqq_process_refs(bfqq) == 1)\n bfqq->bic = bic\n -> record BIC1 to bfqq2\n\n __bfq_insert_request\n new_bfqq = bfq_setup_cooperator\n -> get bfqq3 from bfqq2->new_bfqq\n bfqq_request_freed(bfqq)\n new_bfqq->ref++\n rq->elv.priv[1] = new_bfqq\n -> handle IO by bfqq3\n\nFix the problem by checking bfqq is from merge chain fist. And this\nmight fix a following problem reported by our syzkaller(unreproducible):\n\n==================================================================\nBUG: KASAN: slab-use-after-free in bfq_do_early_stable_merge block/bfq-iosched.c:5692 [inline]\nBUG: KASAN: slab-use-after-free in bfq_do_or_sched_stable_merge block/bfq-iosched.c:5805 [inline]\nBUG: KASAN: slab-use-after-free in bfq_get_queue+0x25b0/0x2610 block/bfq-iosched.c:5889\nWrite of size 1 at addr ffff888123839eb8 by task kworker/0:1H/18595\n\nCPU: 0 PID: 18595 Comm: kworker/0:1H Tainted: G L 6.6.0-07439-gba2303cacfda #6\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014\nWorkqueue: kblockd blk_mq_requeue_work\nCall Trace:\n <TASK>\n __dump_stack lib/dump_stack.c:88 [inline]\n dump_stack_lvl+0x91/0xf0 lib/dump_stack.c:106\n print_address_description mm/kasan/report.c:364 [inline]\n print_report+0x10d/0x610 mm/kasan/report.c:475\n kasan_report+0x8e/0xc0 mm/kasan/report.c:588\n bfq_do_early_stable_merge block/bfq-iosched.c:5692 [inline]\n bfq_do_or_sched_stable_merge block/bfq-iosched.c:5805 [inline]\n bfq_get_queue+0x25b0/0x2610 block/bfq-iosched.c:5889\n bfq_get_bfqq_handle_split+0x169/0x5d0 block/bfq-iosched.c:6757\n bfq_init_rq block/bfq-iosched.c:6876 [inline]\n bfq_insert_request block/bfq-iosched.c:6254 [inline]\n bfq_insert_requests+0x1112/0x5cf0 block/bfq-iosched.c:6304\n blk_mq_insert_request+0x290/0x8d0 block/blk-mq.c:2593\n blk_mq_requeue_work+0x6bc/0xa70 block/blk-mq.c:1502\n process_one_work kernel/workqueue.c:2627 [inline]\n process_scheduled_works+0x432/0x13f0 kernel/workqueue.c:2700\n worker_thread+0x6f2/0x1160 kernel/workqueue.c:2781\n kthread+0x33c/0x440 kernel/kthread.c:388\n ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147\n ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:305\n </TASK>\n\nAllocated by task 20776:\n kasan_save_stack+0x20/0x40 mm/kasan/common.c:45\n kasan_set_track+0x25/0x30 mm/kasan/common.c:52\n __kasan_slab_alloc+0x87/0x90 mm/kasan/common.c:328\n kasan_slab_alloc include/linux/kasan.h:188 [inline]\n slab_post_alloc_hook mm/slab.h:763 [inline]\n slab_alloc_node mm/slub.c:3458 [inline]\n kmem_cache_alloc_node+0x1a4/0x6f0 mm/slub.c:3503\n ioc_create_icq block/blk-ioc.c:370 [inline]\n---truncated---"}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2024-11-08T15:56:22.679Z"}}}, "cveMetadata": {"cveId": "CVE-2024-47706", "state": "PUBLISHED", "dateUpdated": "2024-11-08T15:56:22.679Z", "dateReserved": "2024-09-30T16:00:12.946Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2024-10-21T11:53:40.759Z", "assignerShortName": "Linux"}, "dataVersion": "5.1"}

{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "8E629794-ADD6-44B5-8F8E-B768F34539E0", "versionEndExcluding": "5.10.227", "versionStartIncluding": "4.12", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "4D51C05D-455B-4D8D-89E7-A58E140B864C", "versionEndExcluding": "5.15.168", "versionStartIncluding": "5.11", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "D01BD22E-ACD1-4618-9D01-6116570BE1EE", "versionEndExcluding": "6.1.113", "versionStartIncluding": "5.16", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "D448821D-C085-4CAF-88FA-2DDE7BE21976", "versionEndExcluding": "6.6.54", "versionStartIncluding": "6.2", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "CE94BB8D-B0AB-4563-9ED7-A12122B56EBE", "versionEndExcluding": "6.10.13", "versionStartIncluding": "6.7", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "AB755D26-97F4-43B6-8604-CD076811E181", "versionEndExcluding": "6.11.2", "versionStartIncluding": "6.11", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nblock, bfq: fix possible UAF for bfqq->bic with merge chain\n\n1) initial state, three tasks:\n\n\t\tProcess 1 Process 2\tProcess 3\n\t\t (BIC1) (BIC2)\t\t (BIC3)\n\t\t | \u039b | \u039b\t\t | \u039b\n\t\t | | | |\t\t | |\n\t\t V | V |\t\t V |\n\t\t bfqq1 bfqq2\t\t bfqq3\nprocess ref:\t 1\t\t 1\t\t 1\n\n2) bfqq1 merged to bfqq2:\n\n\t\tProcess 1 Process 2\tProcess 3\n\t\t (BIC1) (BIC2)\t\t (BIC3)\n\t\t | |\t\t | \u039b\n\t\t \\--------------\\|\t\t | |\n\t\t V\t\t V |\n\t\t bfqq1--------->bfqq2\t\t bfqq3\nprocess ref:\t 0\t\t 2\t\t 1\n\n3) bfqq2 merged to bfqq3:\n\n\t\tProcess 1 Process 2\tProcess 3\n\t\t (BIC1) (BIC2)\t\t (BIC3)\n\t here -> \u039b |\t\t |\n\t\t \\--------------\\ \\-------------\\|\n\t\t V\t\t V\n\t\t bfqq1--------->bfqq2---------->bfqq3\nprocess ref:\t 0\t\t 1\t\t 3\n\nIn this case, IO from Process 1 will get bfqq2 from BIC1 first, and then\nget bfqq3 through merge chain, and finially handle IO by bfqq3.\nHowerver, current code will think bfqq2 is owned by BIC1, like initial\nstate, and set bfqq2->bic to BIC1.\n\nbfq_insert_request\n-> by Process 1\n bfqq = bfq_init_rq(rq)\n bfqq = bfq_get_bfqq_handle_split\n bfqq = bic_to_bfqq\n -> get bfqq2 from BIC1\n bfqq->ref++\n rq->elv.priv[0] = bic\n rq->elv.priv[1] = bfqq\n if (bfqq_process_refs(bfqq) == 1)\n bfqq->bic = bic\n -> record BIC1 to bfqq2\n\n __bfq_insert_request\n new_bfqq = bfq_setup_cooperator\n -> get bfqq3 from bfqq2->new_bfqq\n bfqq_request_freed(bfqq)\n new_bfqq->ref++\n rq->elv.priv[1] = new_bfqq\n -> handle IO by bfqq3\n\nFix the problem by checking bfqq is from merge chain fist. And this\nmight fix a following problem reported by our syzkaller(unreproducible):\n\n==================================================================\nBUG: KASAN: slab-use-after-free in bfq_do_early_stable_merge block/bfq-iosched.c:5692 [inline]\nBUG: KASAN: slab-use-after-free in bfq_do_or_sched_stable_merge block/bfq-iosched.c:5805 [inline]\nBUG: KASAN: slab-use-after-free in bfq_get_queue+0x25b0/0x2610 block/bfq-iosched.c:5889\nWrite of size 1 at addr ffff888123839eb8 by task kworker/0:1H/18595\n\nCPU: 0 PID: 18595 Comm: kworker/0:1H Tainted: G L 6.6.0-07439-gba2303cacfda #6\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014\nWorkqueue: kblockd blk_mq_requeue_work\nCall Trace:\n <TASK>\n __dump_stack lib/dump_stack.c:88 [inline]\n dump_stack_lvl+0x91/0xf0 lib/dump_stack.c:106\n print_address_description mm/kasan/report.c:364 [inline]\n print_report+0x10d/0x610 mm/kasan/report.c:475\n kasan_report+0x8e/0xc0 mm/kasan/report.c:588\n bfq_do_early_stable_merge block/bfq-iosched.c:5692 [inline]\n bfq_do_or_sched_stable_merge block/bfq-iosched.c:5805 [inline]\n bfq_get_queue+0x25b0/0x2610 block/bfq-iosched.c:5889\n bfq_get_bfqq_handle_split+0x169/0x5d0 block/bfq-iosched.c:6757\n bfq_init_rq block/bfq-iosched.c:6876 [inline]\n bfq_insert_request block/bfq-iosched.c:6254 [inline]\n bfq_insert_requests+0x1112/0x5cf0 block/bfq-iosched.c:6304\n blk_mq_insert_request+0x290/0x8d0 block/blk-mq.c:2593\n blk_mq_requeue_work+0x6bc/0xa70 block/blk-mq.c:1502\n process_one_work kernel/workqueue.c:2627 [inline]\n process_scheduled_works+0x432/0x13f0 kernel/workqueue.c:2700\n worker_thread+0x6f2/0x1160 kernel/workqueue.c:2781\n kthread+0x33c/0x440 kernel/kthread.c:388\n ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147\n ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:305\n </TASK>\n\nAllocated by task 20776:\n kasan_save_stack+0x20/0x40 mm/kasan/common.c:45\n kasan_set_track+0x25/0x30 mm/kasan/common.c:52\n __kasan_slab_alloc+0x87/0x90 mm/kasan/common.c:328\n kasan_slab_alloc include/linux/kasan.h:188 [inline]\n slab_post_alloc_hook mm/slab.h:763 [inline]\n slab_alloc_node mm/slub.c:3458 [inline]\n kmem_cache_alloc_node+0x1a4/0x6f0 mm/slub.c:3503\n ioc_create_icq block/blk-ioc.c:370 [inline]\n---truncated---"}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: bloque, bfq: corregir posible UAF para bfqq-&gt;bic con cadena de fusi\u00f3n 1) estado inicial, tres tareas: Proceso 1 Proceso 2 Proceso 3 (BIC1) (BIC2) (BIC3) | ? | ? | ? | | | | | | V | V | V | bfqq1 bfqq2 bfqq3 proceso ref: 1 1 1 2) bfqq1 fusionado con bfqq2: Proceso 1 Proceso 2 Proceso 3 (BIC1) (BIC2) (BIC3) | | | ? \\--------------\\| | | VV | bfqq1---------&gt;bfqq2 bfqq3 proceso ref: 0 2 1 3) bfqq2 fusionado con bfqq3: Proceso 1 Proceso 2 Proceso 3 (BIC1) (BIC2) (BIC3) aqu\u00ed -&gt; ? | | \\--------------\\ \\-------------\\| VV bfqq1--------&gt;bfqq2----------&gt;bfqq3 ref. de proceso: 0 1 3 En este caso, la IO del Proceso 1 obtendr\u00e1 primero bfqq2 de BIC1, y luego obtendr\u00e1 bfqq3 a trav\u00e9s de la cadena de fusi\u00f3n, y finalmente manejar\u00e1 la IO por bfqq3. Sin embargo, el c\u00f3digo actual pensar\u00e1 que bfqq2 es propiedad de BIC1, como estado inicial, y establecer\u00e1 bfqq2-&gt;bic en BIC1. bfq_insert_request -&gt; por Proceso 1 bfqq = bfq_init_rq(rq) bfqq = bfq_get_bfqq_handle_split bfqq = bic_to_bfqq -&gt; obtener bfqq2 de BIC1 bfqq-&gt;ref++ rq-&gt;elv.priv[0] = bic rq-&gt;elv.priv[1] = bfqq si (bfqq_process_refs(bfqq) == 1) bfqq-&gt;bic = bic -&gt; grabar BIC1 en bfqq2 __bfq_insert_request new_bfqq = bfq_setup_cooperator -&gt; obtener bfqq3 de bfqq2-&gt;new_bfqq bfqq_request_freed(bfqq) new_bfqq-&gt;ref++ rq-&gt;elv.priv[1] = new_bfqq -&gt; manejar IO por bfqq3 Solucione el problema verificando que bfqq sea primero de la cadena de fusi\u00f3n. Y esto podr\u00eda solucionar el siguiente problema informado por nuestro syzkaller (irreproducible): ===================================================================== ERROR: KASAN: slab-use-after-free en el bloque bfq_do_early_stable_merge/bfq-iosched.c:5692 [en l\u00ednea] ERROR: KASAN: slab-use-after-free en el bloque bfq_do_or_sched_stable_merge/bfq-iosched.c:5805 [en l\u00ednea] ERROR: KASAN: slab-use-after-free en el bloque bfq_get_queue+0x25b0/0x2610/bfq-iosched.c:5889 Escribir de tama\u00f1o 1 en la direcci\u00f3n ffff888123839eb8 por la tarea kworker/0:1H/18595 CPU: 0 PID: 18595 Comm: kworker/0:1H Contaminado: GL 6.6.0-07439-gba2303cacfda #6 Nombre del hardware: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 Cola de trabajo: kblockd blk_mq_requeue_work Rastreo de llamadas: __dump_stack lib/dump_stack.c:88 [en l\u00ednea] dump_stack_lvl+0x91/0xf0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [en l\u00ednea] imprimir_informe+0x10d/0x610 mm/kasan/report.c:475 kasan_report+0x8e/0xc0 mm/kasan/report.c:588 bloque bfq_do_early_stable_merge/bfq-iosched.c:5692 [en l\u00ednea] bloque bfq_do_or_sched_stable_merge/bfq-iosched.c:5805 [en l\u00ednea] bloque bfq_get_queue+0x25b0/0x2610/bfq-iosched.c:5889 bloque bfq_get_bfqq_handle_split+0x169/0x5d0/bfq-iosched.c:6757 bloque bfq_init_rq/bfq-iosched.c:6876 [en l\u00ednea] bloque bfq_insert_request/bfq-iosched.c:6254 [en l\u00ednea] bloque bfq_insert_requests+0x1112/0x5cf0/bfq-iosched.c:6304 bloque blk_mq_insert_request+0x290/0x8d0/blk-mq.c:2593 bloque blk_mq_requeue_work+0x6bc/0xa70/blk-mq.c:1502 proceso_uno_trabajo kernel/workqueue.c:2627 [en l\u00ednea] proceso_trabajos_programados+0x432/0x13f0 kernel/workqueue.c:2700 subproceso_trabajador+0x6f2/0x1160 kernel/workqueue.c:2781 subproceso_k+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:305 Asignado por la tarea 20776: kasan_save_stack+0x20/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 __kasan_slab_alloc+0x87/0x90 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:188 [en l\u00ednea] slab_post_alloc_hook mm/slab.h:763 [en l\u00ednea] slab_alloc_node mm/slub.c:3458 [en l\u00ednea] kmem_cache_alloc_node+0x1a4/0x6f0 mm/slub.c:3503 ioc_create_icq block/blk-ioc.c:370 [en l\u00ednea] ---truncado---"}], "id": "CVE-2024-47706", "lastModified": "2024-11-08T16:15:25.847", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 5.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}]}, "published": "2024-10-21T12:15:07.120", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/18ad4df091dd5d067d2faa8fce1180b79f7041a7"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/6d130db286ad0ea392c96ebb2551acf0d7308048"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/7faed2896d78e48ec96229e73b30b0af6c00a9aa"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/880692ee233ba63808182705b3333403413b58f5"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/8aa9de02a4be2e7006e636816ce19b0d667ceaa3"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a9bdd5b36887d2bacb8bc777fd18317c99fc2587"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/bc2140534b2aae752e4f7cb4489642dbb5ec4777"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/ddbdaad123254fb53e32480cb74a486a6868b1e0"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/e1277ae780cca4e69ef5468d4582dfd48f0b8320"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-416"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: block, bfq: fix possible UAF for bfqq-&gt;bic with merge chain", "id": "2320238", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2320238"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "details": ["In the Linux kernel, the following vulnerability has been resolved:\nblock, bfq: fix possible UAF for bfqq->bic with merge chain\n1) initial state, three tasks:\nProcess 1 Process 2Process 3\n(BIC1) (BIC2) (BIC3)\n| \u039b | \u039b | \u039b\n| | | | | |\nV | V | V |\nbfqq1 bfqq2 bfqq3\nprocess ref: 1 1 1\n2) bfqq1 merged to bfqq2:\nProcess 1 Process 2Process 3\n(BIC1) (BIC2) (BIC3)\n| | | \u039b\n\\--------------\\| | |\nV V |\nbfqq1--------->bfqq2 bfqq3\nprocess ref: 0 2 1\n3) bfqq2 merged to bfqq3:\nProcess 1 Process 2Process 3\n(BIC1) (BIC2) (BIC3)\nhere -> \u039b | |\n\\--------------\\ \\-------------\\|\nV V\nbfqq1--------->bfqq2---------->bfqq3\nprocess ref: 0 1 3\nIn this case, IO from Process 1 will get bfqq2 from BIC1 first, and then\nget bfqq3 through merge chain, and finially handle IO by bfqq3.\nHowerver, current code will think bfqq2 is owned by BIC1, like initial\nstate, and set bfqq2->bic to BIC1.\nbfq_insert_request\n-> by Process 1\nbfqq = bfq_init_rq(rq)\nbfqq = bfq_get_bfqq_handle_split\nbfqq = bic_to_bfqq\n-> get bfqq2 from BIC1\nbfqq->ref++\nrq->elv.priv[0] = bic\nrq->elv.priv[1] = bfqq\nif (bfqq_process_refs(bfqq) == 1)\nbfqq->bic = bic\n-> record BIC1 to bfqq2\n__bfq_insert_request\nnew_bfqq = bfq_setup_cooperator\n-> get bfqq3 from bfqq2->new_bfqq\nbfqq_request_freed(bfqq)\nnew_bfqq->ref++\nrq->elv.priv[1] = new_bfqq\n-> handle IO by bfqq3\nFix the problem by checking bfqq is from merge chain fist. And this\nmight fix a following problem reported by our syzkaller(unreproducible):\n==================================================================\nBUG: KASAN: slab-use-after-free in bfq_do_early_stable_merge block/bfq-iosched.c:5692 [inline]\nBUG: KASAN: slab-use-after-free in bfq_do_or_sched_stable_merge block/bfq-iosched.c:5805 [inline]\nBUG: KASAN: slab-use-after-free in bfq_get_queue+0x25b0/0x2610 block/bfq-iosched.c:5889\nWrite of size 1 at addr ffff888123839eb8 by task kworker/0:1H/18595\nCPU: 0 PID: 18595 Comm: kworker/0:1H Tainted: G L 6.6.0-07439-gba2303cacfda #6\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014\nWorkqueue: kblockd blk_mq_requeue_work\nCall Trace:\n<TASK>\n__dump_stack lib/dump_stack.c:88 [inline]\ndump_stack_lvl+0x91/0xf0 lib/dump_stack.c:106\nprint_address_description mm/kasan/report.c:364 [inline]\nprint_report+0x10d/0x610 mm/kasan/report.c:475\nkasan_report+0x8e/0xc0 mm/kasan/report.c:588\nbfq_do_early_stable_merge block/bfq-iosched.c:5692 [inline]\nbfq_do_or_sched_stable_merge block/bfq-iosched.c:5805 [inline]\nbfq_get_queue+0x25b0/0x2610 block/bfq-iosched.c:5889\nbfq_get_bfqq_handle_split+0x169/0x5d0 block/bfq-iosched.c:6757\nbfq_init_rq block/bfq-iosched.c:6876 [inline]\nbfq_insert_request block/bfq-iosched.c:6254 [inline]\nbfq_insert_requests+0x1112/0x5cf0 block/bfq-iosched.c:6304\nblk_mq_insert_request+0x290/0x8d0 block/blk-mq.c:2593\nblk_mq_requeue_work+0x6bc/0xa70 block/blk-mq.c:1502\nprocess_one_work kernel/workqueue.c:2627 [inline]\nprocess_scheduled_works+0x432/0x13f0 kernel/workqueue.c:2700\nworker_thread+0x6f2/0x1160 kernel/workqueue.c:2781\nkthread+0x33c/0x440 kernel/kthread.c:388\nret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147\nret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:305\n</TASK>\nAllocated by task 20776:\nkasan_save_stack+0x20/0x40 mm/kasan/common.c:45\nkasan_set_track+0x25/0x30 mm/kasan/common.c:52\n__kasan_slab_alloc+0x87/0x90 mm/kasan/common.c:328\nkasan_slab_alloc include/linux/kasan.h:188 [inline]\nslab_post_alloc_hook mm/slab.h:763 [inline]\nslab_alloc_node mm/slub.c:3458 [inline]\nkmem_cache_alloc_node+0x1a4/0x6f0 mm/slub.c:3503\nioc_create_icq block/blk-ioc.c:370 [inline]\n---truncated---"], "name": "CVE-2024-47706", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Will not fix", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Will not fix", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Will not fix", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2024-10-21T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2024-47706\nhttps://nvd.nist.gov/vuln/detail/CVE-2024-47706\nhttps://lore.kernel.org/linux-cve-announce/2024102116-CVE-2024-47706-7312@gregkh/T"], "threat_severity": "Moderate"}