CVSS: -EPSS: 0%CPEs: 7EXPL: 0CVE-2024-47706 – block, bfq: fix possible UAF for bfqq->bic with merge chain
https://notcve.org/view.php?id=CVE-2024-47706
In the Linux kernel, the following vulnerability has been resolved: block, bfq: fix possible UAF for bfqq->bic with merge chain 1) initial state, three tasks: Process 1 Process 2 Process 3 (BIC1) (BIC2) (BIC3) | Λ | Λ | Λ | | | | | | V | V | V | bfqq1 bfqq2 bfqq3 process ref: 1 1 1 2) bfqq1 merged to bfqq2: Process 1 Process 2 Process 3 (BIC1) (BIC2) (BIC3) | | | Λ \--------------\| | | V V | bfqq1--------->bfqq2 bfqq3 process ref: 0 2 1 3) bfqq2 merged to bfqq3: Process 1 Process 2 Process 3 (BIC1) (BIC2) (BIC3) here -> Λ | | \--------------\ \-------------\| V V bfqq1--------->bfqq2---------->bfqq3 process ref: 0 1 3 In this case, IO from Process 1 will get bfqq2 from BIC1 first, and then get bfqq3 through merge chain, and finially handle IO by bfqq3. Howerver, current code will think bfqq2 is owned by BIC1, like initial state, and set bfqq2->bic to BIC1. bfq_insert_request -> by Process 1 bfqq = bfq_init_rq(rq) bfqq = bfq_get_bfqq_handle_split bfqq = bic_to_bfqq -> get bfqq2 from BIC1 bfqq->ref++ rq->elv.priv[0] = bic rq->elv.priv[1] = bfqq if (bfqq_process_refs(bfqq) == 1) bfqq->bic = bic -> record BIC1 to bfqq2 __bfq_insert_request new_bfqq = bfq_setup_cooperator -> get bfqq3 from bfqq2->new_bfqq bfqq_request_freed(bfqq) new_bfqq->ref++ rq->elv.priv[1] = new_bfqq -> handle IO by bfqq3 Fix the problem by checking bfqq is from merge chain fist. And this might fix a following problem reported by our syzkaller(unreproducible): ================================================================== BUG: KASAN: slab-use-after-free in bfq_do_early_stable_merge block/bfq-iosched.c:5692 [inline] BUG: KASAN: slab-use-after-free in bfq_do_or_sched_stable_merge block/bfq-iosched.c:5805 [inline] BUG: KASAN: slab-use-after-free in bfq_get_queue+0x25b0/0x2610 block/bfq-iosched.c:5889 Write of size 1 at addr ffff888123839eb8 by task kworker/0:1H/18595 CPU: 0 PID: 18595 Comm: kworker/0:1H Tainted: G L 6.6.0-07439-gba2303cacfda #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 Workqueue: kblockd blk_mq_requeue_work Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x91/0xf0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0x10d/0x610 mm/kasan/report.c:475 kasan_report+0x8e/0xc0 mm/kasan/report.c:588 bfq_do_early_stable_merge block/bfq-iosched.c:5692 [inline] bfq_do_or_sched_stable_merge block/bfq-iosched.c:5805 [inline] bfq_get_queue+0x25b0/0x2610 block/bfq-iosched.c:5889 bfq_get_bfqq_handle_split+0x169/0x5d0 block/bfq-iosched.c:6757 bfq_init_rq block/bfq-iosched.c:6876 [inline] bfq_insert_request block/bfq-iosched.c:6254 [inline] bfq_insert_requests+0x1112/0x5cf0 block/bfq-iosched.c:6304 blk_mq_insert_request+0x290/0x8d0 block/blk-mq.c:2593 blk_mq_requeue_work+0x6bc/0xa70 block/blk-mq.c:1502 process_one_work kernel/workqueue.c:2627 [inline] process_scheduled_works+0x432/0x13f0 kernel/workqueue.c:2700 worker_thread+0x6f2/0x1160 kernel/workqueue.c:2781 kthread+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 </TASK> Allocated by task 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 [inline] slab_post_alloc_hook mm/slab.h:763 [inline] slab_alloc_node mm/slub.c:3458 [inline] kmem_cache_alloc_node+0x1a4/0x6f0 mm/slub.c:3503 ioc_create_icq block/blk-ioc.c:370 [inline] ---truncated--- • https://git.kernel.org/stable/c/36eca894832351feed9072d0f97eb06fc9482ca4 https://git.kernel.org/stable/c/e1277ae780cca4e69ef5468d4582dfd48f0b8320 https://git.kernel.org/stable/c/8aa9de02a4be2e7006e636816ce19b0d667ceaa3 https://git.kernel.org/stable/c/ddbdaad123254fb53e32480cb74a486a6868b1e0 https://git.kernel.org/stable/c/7faed2896d78e48ec96229e73b30b0af6c00a9aa https://git.kernel.org/stable/c/880692ee233ba63808182705b3333403413b58f5 https://git.kernel.org/stable/c/6d130db286ad0ea392c96ebb2551acf0d7308048 https://git.kernel.org/stable/c/18ad4df091dd5d067d2faa8fce1180b79 •
CVSS: -EPSS: 0%CPEs: 7EXPL: 0CVE-2024-47705 – block: fix potential invalid pointer dereference in blk_add_partition
https://notcve.org/view.php?id=CVE-2024-47705
In the Linux kernel, the following vulnerability has been resolved: block: fix potential invalid pointer dereference in blk_add_partition The blk_add_partition() function initially used a single if-condition (IS_ERR(part)) to check for errors when adding a partition. This was modified to handle the specific case of -ENXIO separately, allowing the function to proceed without logging the error in this case. However, this change unintentionally left a path where md_autodetect_dev() could be called without confirming that part is a valid pointer. This commit separates the error handling logic by splitting the initial if-condition, improving code readability and handling specific error scenarios explicitly. The function now distinguishes the general error case from -ENXIO without altering the existing behavior of md_autodetect_dev() calls. • https://git.kernel.org/stable/c/b72053072c0bbe9f1cdfe2ffa3c201c185da2201 https://git.kernel.org/stable/c/4bc4272e2506941c3f3d4fb8b0c659ee814dcf6f https://git.kernel.org/stable/c/cc4d21d9492db4e534d3e01253cf885c90dd2a8b https://git.kernel.org/stable/c/64cf2a39202ca2d9df5ee70eb310b6141ce2b8ed https://git.kernel.org/stable/c/80f5bfbb80ea1615290dbc24f49d3d8c86db58fe https://git.kernel.org/stable/c/652039ba477c9a4ab43740cf2cb0d068d53508c2 https://git.kernel.org/stable/c/afe53ea9b378c376101d99d216f13b6256f75189 https://git.kernel.org/stable/c/26e197b7f9240a4ac301dd0ad520c0c69 •
CVSS: -EPSS: 0%CPEs: 4EXPL: 0CVE-2024-47704 – drm/amd/display: Check link_res->hpo_dp_link_enc before using it
https://notcve.org/view.php?id=CVE-2024-47704
In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Check link_res->hpo_dp_link_enc before using it [WHAT & HOW] Functions dp_enable_link_phy and dp_disable_link_phy can pass link_res without initializing hpo_dp_link_enc and it is necessary to check for null before dereferencing. This fixes 2 FORWARD_NULL issues reported by Coverity. • https://git.kernel.org/stable/c/be2ca7a2c1561390d28bf2f92654d819659ba510 https://git.kernel.org/stable/c/530e29452b955c30cf2102fa4d07420dc6e0c953 https://git.kernel.org/stable/c/0508a4e95ac1aefd851ceb97ea050d8abb93262c https://git.kernel.org/stable/c/0beca868cde8742240cd0038141c30482d2b7eb8 •
CVSS: -EPSS: 0%CPEs: 3EXPL: 0CVE-2024-47703 – bpf, lsm: Add check for BPF LSM return value
https://notcve.org/view.php?id=CVE-2024-47703
In the Linux kernel, the following vulnerability has been resolved: bpf, lsm: Add check for BPF LSM return value A bpf prog returning a positive number attached to file_alloc_security hook makes kernel panic. This happens because file system can not filter out the positive number returned by the LSM prog using IS_ERR, and misinterprets this positive number as a file pointer. Given that hook file_alloc_security never returned positive number before the introduction of BPF LSM, and other BPF LSM hooks may encounter similar issues, this patch adds LSM return value check in verifier, to ensure no unexpected value is returned. • https://git.kernel.org/stable/c/520b7aa00d8cd8e411ecc09f63a2acd90feb6d29 https://git.kernel.org/stable/c/1050727d83e70449991c29dd1cf29fe936a63da3 https://git.kernel.org/stable/c/27ca3e20fe80be85a92b10064dfeb56cb2564b1c https://git.kernel.org/stable/c/5d99e198be279045e6ecefe220f5c52f8ce9bfd5 •
CVSS: -EPSS: 0%CPEs: 3EXPL: 0CVE-2024-47702 – bpf: Fail verification for sign-extension of packet data/data_end/data_meta
https://notcve.org/view.php?id=CVE-2024-47702
In the Linux kernel, the following vulnerability has been resolved: bpf: Fail verification for sign-extension of packet data/data_end/data_meta syzbot reported a kernel crash due to commit 1f1e864b6555 ("bpf: Handle sign-extenstin ctx member accesses"). The reason is due to sign-extension of 32-bit load for packet data/data_end/data_meta uapi field. The original code looks like: r2 = *(s32 *)(r1 + 76) /* load __sk_buff->data */ r3 = *(u32 *)(r1 + 80) /* load __sk_buff->data_end */ r0 = r2 r0 += 8 if r3 > r0 goto +1 ... Note that __sk_buff->data load has 32-bit sign extension. After verification and convert_ctx_accesses(), the final asm code looks like: r2 = *(u64 *)(r1 +208) r2 = (s32)r2 r3 = *(u64 *)(r1 +80) r0 = r2 r0 += 8 if r3 > r0 goto pc+1 ... Note that 'r2 = (s32)r2' may make the kernel __sk_buff->data address invalid which may cause runtime failure. Currently, in C code, typically we have void *data = (void *)(long)skb->data; void *data_end = (void *)(long)skb->data_end; ... and it will generate r2 = *(u64 *)(r1 +208) r3 = *(u64 *)(r1 +80) r0 = r2 r0 += 8 if r3 > r0 goto pc+1 If we allow sign-extension, void *data = (void *)(long)(int)skb->data; void *data_end = (void *)(long)skb->data_end; ... the generated code looks like r2 = *(u64 *)(r1 +208) r2 <<= 32 r2 s>>= 32 r3 = *(u64 *)(r1 +80) r0 = r2 r0 += 8 if r3 > r0 goto pc+1 and this will cause verification failure since "r2 <<= 32" is not allowed as "r2" is a packet pointer. To fix this issue for case r2 = *(s32 *)(r1 + 76) /* load __sk_buff->data */ this patch added additional checking in is_valid_access() callback function for packet data/data_end/data_meta access. If those accesses are with sign-extenstion, the verification will fail. [1] https://lore.kernel.org/bpf/000000000000c90eee061d236d37@google.com/ • https://git.kernel.org/stable/c/1f1e864b65554e33fe74e3377e58b12f4302f2eb https://git.kernel.org/stable/c/f1620c93a1ec950d87ef327a565d3907736d3340 https://git.kernel.org/stable/c/f09757fe97a225ae505886eac572e4cbfba96537 https://git.kernel.org/stable/c/92de36080c93296ef9005690705cba260b9bd68a •