CVE-2024-50279 – dm cache: fix out-of-bounds access to the dirty bitset when resizing
https://notcve.org/view.php?id=CVE-2024-50279
In the Linux kernel, the following vulnerability has been resolved: dm cache: fix out-of-bounds access to the dirty bitset when resizing dm-cache checks the dirty bits of the cache blocks to be dropped when shrinking the fast device, but an index bug in bitset iteration causes out-of-bounds access. Reproduce steps: 1. create a cache device of 1024 cache blocks (128 bytes dirty bitset) dmsetup create cmeta --table "0 8192 linear /dev/sdc 0" dmsetup create cdata --table "0 131072 linear /dev/sdc 8192" dmsetup create corig --table "0 524288 linear /dev/sdc 262144" dd if=/dev/zero of=/dev/mapper/cmeta bs=4k count=1 oflag=direct dmsetup create cache --table "0 524288 cache /dev/mapper/cmeta \ /dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0" 2. shrink the fast device to 512 cache blocks, triggering out-of-bounds access to the dirty bitset (offset 0x80) dmsetup suspend cache dmsetup reload cdata --table "0 65536 linear /dev/sdc 8192" dmsetup resume cdata dmsetup resume cache KASAN reports: BUG: KASAN: vmalloc-out-of-bounds in cache_preresume+0x269/0x7b0 Read of size 8 at addr ffffc900000f3080 by task dmsetup/131 (...snip...) The buggy address belongs to the virtual mapping at [ffffc900000f3000, ffffc900000f5000) created by: cache_ctr+0x176a/0x35f0 (...snip...) Memory state around the buggy address: ffffc900000f2f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc900000f3000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffffc900000f3080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ^ ffffc900000f3100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc900000f3180: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 Fix by making the index post-incremented. • https://git.kernel.org/stable/c/f494a9c6b1b6dd9a9f21bbb75d9210d478eeb498 https://git.kernel.org/stable/c/4fa4feb873cea0e9d6ff883b37cca6f33169d8b4 https://git.kernel.org/stable/c/8501e38dc9e0060814c4085815fc83da3e6d43bf https://git.kernel.org/stable/c/ee1f74925717ab36f6a091104c170639501ce818 https://git.kernel.org/stable/c/ff1dd8a04c30e8d4e2fd5c83198ca672eb6a9e7f https://git.kernel.org/stable/c/56507203e1b6127967ec2b51fb0b23a0d4af1334 https://git.kernel.org/stable/c/e57648ce325fa405fe6bbd0e6a618ced7c301a2d https://git.kernel.org/stable/c/3b02c40ff10fdf83cc545850db208de85 •
CVE-2024-50278 – dm cache: fix potential out-of-bounds access on the first resume
https://notcve.org/view.php?id=CVE-2024-50278
In the Linux kernel, the following vulnerability has been resolved: dm cache: fix potential out-of-bounds access on the first resume Out-of-bounds access occurs if the fast device is expanded unexpectedly before the first-time resume of the cache table. This happens because expanding the fast device requires reloading the cache table for cache_create to allocate new in-core data structures that fit the new size, and the check in cache_preresume is not performed during the first resume, leading to the issue. Reproduce steps: 1. prepare component devices: dmsetup create cmeta --table "0 8192 linear /dev/sdc 0" dmsetup create cdata --table "0 65536 linear /dev/sdc 8192" dmsetup create corig --table "0 524288 linear /dev/sdc 262144" dd if=/dev/zero of=/dev/mapper/cmeta bs=4k count=1 oflag=direct 2. load a cache table of 512 cache blocks, and deliberately expand the fast device before resuming the cache, making the in-core data structures inadequate. dmsetup create cache --notable dmsetup reload cache --table "0 524288 cache /dev/mapper/cmeta \ /dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0" dmsetup reload cdata --table "0 131072 linear /dev/sdc 8192" dmsetup resume cdata dmsetup resume cache 3. suspend the cache to write out the in-core dirty bitset and hint array, leading to out-of-bounds access to the dirty bitset at offset 0x40: dmsetup suspend cache KASAN reports: BUG: KASAN: vmalloc-out-of-bounds in is_dirty_callback+0x2b/0x80 Read of size 8 at addr ffffc90000085040 by task dmsetup/90 (...snip...) The buggy address belongs to the virtual mapping at [ffffc90000085000, ffffc90000087000) created by: cache_ctr+0x176a/0x35f0 (...snip...) Memory state around the buggy address: ffffc90000084f00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc90000084f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 >ffffc90000085000: 00 00 00 00 00 00 00 00 f8 f8 f8 f8 f8 f8 f8 f8 ^ ffffc90000085080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc90000085100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 Fix by checking the size change on the first resume. • https://git.kernel.org/stable/c/f494a9c6b1b6dd9a9f21bbb75d9210d478eeb498 https://git.kernel.org/stable/c/e492f71854ce03474d49e87fd98b8df1f7cd1d2d https://git.kernel.org/stable/c/2222b0929d00e2d13732b799b63be391b5de4492 https://git.kernel.org/stable/c/483b7261b35a9d369082ab298a6670912243f0be https://git.kernel.org/stable/c/fdef3b94dfebd57e3077a578b6e309a2bb6fa688 https://git.kernel.org/stable/c/c52ec00cb2f9bebfada22edcc0db385b910a1cdb https://git.kernel.org/stable/c/036dd6e3d2638103e0092864577ea1d091466b86 https://git.kernel.org/stable/c/13ed3624c6ef283acefa4cc42cc8ae54f •
CVE-2024-50277 – dm: fix a crash if blk_alloc_disk fails
https://notcve.org/view.php?id=CVE-2024-50277
In the Linux kernel, the following vulnerability has been resolved: dm: fix a crash if blk_alloc_disk fails If blk_alloc_disk fails, the variable md->disk is set to an error value. cleanup_mapped_device will see that md->disk is non-NULL and it will attempt to access it, causing a crash on this statement "md->disk->private_data = NULL;". • https://git.kernel.org/stable/c/d7aec2a06730b774a97caaf48cbbc58330a85829 https://git.kernel.org/stable/c/fed13a5478680614ba97fc87e71f16e2e197912e •
CVE-2024-50275 – arm64/sve: Discard stale CPU state when handling SVE traps
https://notcve.org/view.php?id=CVE-2024-50275
In the Linux kernel, the following vulnerability has been resolved: arm64/sve: Discard stale CPU state when handling SVE traps The logic for handling SVE traps manipulates saved FPSIMD/SVE state incorrectly, and a race with preemption can result in a task having TIF_SVE set and TIF_FOREIGN_FPSTATE clear even though the live CPU state is stale (e.g. with SVE traps enabled). This has been observed to result in warnings from do_sve_acc() where SVE traps are not expected while TIF_SVE is set: | if (test_and_set_thread_flag(TIF_SVE)) | WARN_ON(1); /* SVE access shouldn't have trapped */ Warnings of this form have been reported intermittently, e.g. https://lore.kernel.org/linux-arm-kernel/CA+G9fYtEGe_DhY2Ms7+L7NKsLYUomGsgqpdBj+QwDLeSg=JhGg@mail.gmail.com/ https://lore.kernel.org/linux-arm-kernel/000000000000511e9a060ce5a45c@google.com/ The race can occur when the SVE trap handler is preempted before and after manipulating the saved FPSIMD/SVE state, starting and ending on the same CPU, e.g. | void do_sve_acc(unsigned long esr, struct pt_regs *regs) | { | // Trap on CPU 0 with TIF_SVE clear, SVE traps enabled | // task->fpsimd_cpu is 0. | // per_cpu_ptr(&fpsimd_last_state, 0) is task. | | ... | | // Preempted; migrated from CPU 0 to CPU 1. | // TIF_FOREIGN_FPSTATE is set. | | get_cpu_fpsimd_context(); | | if (test_and_set_thread_flag(TIF_SVE)) | WARN_ON(1); /* SVE access shouldn't have trapped */ | | sve_init_regs() { | if (!test_thread_flag(TIF_FOREIGN_FPSTATE)) { | ... | } else { | fpsimd_to_sve(current); | current->thread.fp_type = FP_STATE_SVE; | } | } | | put_cpu_fpsimd_context(); | | // Preempted; migrated from CPU 1 to CPU 0. | // task->fpsimd_cpu is still 0 | // If per_cpu_ptr(&fpsimd_last_state, 0) is still task then: | // - Stale HW state is reused (with SVE traps enabled) | // - TIF_FOREIGN_FPSTATE is cleared | // - A return to userspace skips HW state restore | } Fix the case where the state is not live and TIF_FOREIGN_FPSTATE is set by calling fpsimd_flush_task_state() to detach from the saved CPU state. This ensures that a subsequent context switch will not reuse the stale CPU state, and will instead set TIF_FOREIGN_FPSTATE, forcing the new state to be reloaded from memory prior to a return to userspace. • https://git.kernel.org/stable/c/cccb78ce89c45a4414db712be4986edfb92434bd https://git.kernel.org/stable/c/51d3d80a6dc314982a9a0aeb0961085922a1aa15 https://git.kernel.org/stable/c/de529504b3274d57caf8f66800b714b0d3ee235a https://git.kernel.org/stable/c/51d11ea0250d6ee461987403bbfd4b2abb5613a7 https://git.kernel.org/stable/c/fa9ce027b3ce37a2bb173bf2553b5caa438fd8c9 https://git.kernel.org/stable/c/751ecf6afd6568adc98f2a6052315552c0483d18 •
CVE-2024-50273 – btrfs: reinitialize delayed ref list after deleting it from the list
https://notcve.org/view.php?id=CVE-2024-50273
In the Linux kernel, the following vulnerability has been resolved: btrfs: reinitialize delayed ref list after deleting it from the list At insert_delayed_ref() if we need to update the action of an existing ref to BTRFS_DROP_DELAYED_REF, we delete the ref from its ref head's ref_add_list using list_del(), which leaves the ref's add_list member not reinitialized, as list_del() sets the next and prev members of the list to LIST_POISON1 and LIST_POISON2, respectively. If later we end up calling drop_delayed_ref() against the ref, which can happen during merging or when destroying delayed refs due to a transaction abort, we can trigger a crash since at drop_delayed_ref() we call list_empty() against the ref's add_list, which returns false since the list was not reinitialized after the list_del() and as a consequence we call list_del() again at drop_delayed_ref(). This results in an invalid list access since the next and prev members are set to poison pointers, resulting in a splat if CONFIG_LIST_HARDENED and CONFIG_DEBUG_LIST are set or invalid poison pointer dereferences otherwise. So fix this by deleting from the list with list_del_init() instead. • https://git.kernel.org/stable/c/1d57ee941692d0cc928526e21a1557b2ae3e11db https://git.kernel.org/stable/c/2fd0948a483e9cb2d669c7199bc620a21c97673d https://git.kernel.org/stable/c/93c5b8decc0ef39ba84f4211d2db6da0a4aefbeb https://git.kernel.org/stable/c/bf0b0c6d159767c0d1c21f793950d78486690ee0 https://git.kernel.org/stable/c/c24fa427fc0ae827b2a3a07f13738cbf82c3f851 https://git.kernel.org/stable/c/2cb1a73d1d44a1c11b0ee5eeced765dd80ec48e6 https://git.kernel.org/stable/c/f04be6d68f715c1473a8422fc0460f57b5e99931 https://git.kernel.org/stable/c/50a3933760b427759afdd23156a7280a1 •