Total
33658 CVE
| CVE | Vendors | Products | Updated | CVSS v3.1 |
|---|---|---|---|---|
| CVE-2024-47715 | 2 Linux, Redhat | 2 Linux Kernel, Enterprise Linux | 2025-05-04 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: mt7915: fix oops on non-dbdc mt7986 mt7915_band_config() sets band_idx = 1 on the main phy for mt7986 with MT7975_ONE_ADIE or MT7976_ONE_ADIE. Commit 0335c034e726 ("wifi: mt76: fix race condition related to checking tx queue fill status") introduced a dereference of the phys array indirectly indexed by band_idx via wcid->phy_idx in mt76_wcid_cleanup(). This caused the following Oops on affected mt7986 devices: Unable to handle kernel read from unreadable memory at virtual address 0000000000000024 Mem abort info: ESR = 0x0000000096000005 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x05: level 1 translation fault Data abort info: ISV = 0, ISS = 0x00000005 CM = 0, WnR = 0 user pgtable: 4k pages, 39-bit VAs, pgdp=0000000042545000 [0000000000000024] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000 Internal error: Oops: 0000000096000005 [#1] SMP Modules linked in: ... mt7915e mt76_connac_lib mt76 mac80211 cfg80211 ... CPU: 2 PID: 1631 Comm: hostapd Not tainted 5.15.150 #0 Hardware name: ZyXEL EX5700 (Telenor) (DT) pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : mt76_wcid_cleanup+0x84/0x22c [mt76] lr : mt76_wcid_cleanup+0x64/0x22c [mt76] sp : ffffffc00a803700 x29: ffffffc00a803700 x28: ffffff80008f7300 x27: ffffff80003f3c00 x26: ffffff80000a7880 x25: ffffffc008c26e00 x24: 0000000000000001 x23: ffffffc000a68114 x22: 0000000000000000 x21: ffffff8004172cc8 x20: ffffffc00a803748 x19: ffffff8004152020 x18: 0000000000000000 x17: 00000000000017c0 x16: ffffffc008ef5000 x15: 0000000000000be0 x14: ffffff8004172e28 x13: ffffff8004172e28 x12: 0000000000000000 x11: 0000000000000000 x10: ffffff8004172e30 x9 : ffffff8004172e28 x8 : 0000000000000000 x7 : ffffff8004156020 x6 : 0000000000000000 x5 : 0000000000000031 x4 : 0000000000000000 x3 : 0000000000000001 x2 : 0000000000000000 x1 : ffffff80008f7300 x0 : 0000000000000024 Call trace: mt76_wcid_cleanup+0x84/0x22c [mt76] __mt76_sta_remove+0x70/0xbc [mt76] mt76_sta_state+0x8c/0x1a4 [mt76] mt7915_eeprom_get_power_delta+0x11e4/0x23a0 [mt7915e] drv_sta_state+0x144/0x274 [mac80211] sta_info_move_state+0x1cc/0x2a4 [mac80211] sta_set_sinfo+0xaf8/0xc24 [mac80211] sta_info_destroy_addr_bss+0x4c/0x6c [mac80211] ieee80211_color_change_finish+0x1c08/0x1e70 [mac80211] cfg80211_check_station_change+0x1360/0x4710 [cfg80211] genl_family_rcv_msg_doit+0xb4/0x110 genl_rcv_msg+0xd0/0x1bc netlink_rcv_skb+0x58/0x120 genl_rcv+0x34/0x50 netlink_unicast+0x1f0/0x2ec netlink_sendmsg+0x198/0x3d0 ____sys_sendmsg+0x1b0/0x210 ___sys_sendmsg+0x80/0xf0 __sys_sendmsg+0x44/0xa0 __arm64_sys_sendmsg+0x20/0x30 invoke_syscall.constprop.0+0x4c/0xe0 do_el0_svc+0x40/0xd0 el0_svc+0x14/0x4c el0t_64_sync_handler+0x100/0x110 el0t_64_sync+0x15c/0x160 Code: d2800002 910092c0 52800023 f9800011 (885f7c01) ---[ end trace 7e42dd9a39ed2281 ]--- Fix by using mt76_dev_phy() which will map band_idx to the correct phy for all hardware combinations. | ||||
| CVE-2024-47703 | 2 Linux, Redhat | 2 Linux Kernel, Enterprise Linux | 2025-05-04 | 5.5 Medium |
| 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. | ||||
| CVE-2024-47702 | 1 Linux | 1 Linux Kernel | 2025-05-04 | 5.5 Medium |
| 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/ | ||||
| CVE-2024-47658 | 1 Linux | 1 Linux Kernel | 2025-05-04 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: crypto: stm32/cryp - call finalize with bh disabled The finalize operation in interrupt mode produce a produces a spinlock recursion warning. The reason is the fact that BH must be disabled during this process. | ||||
| CVE-2024-46869 | 1 Linux | 1 Linux Kernel | 2025-05-04 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: Bluetooth: btintel_pcie: Allocate memory for driver private data Fix driver not allocating memory for struct btintel_data which is used to store internal data. | ||||
| CVE-2024-46864 | 2 Linux, Redhat | 2 Linux Kernel, Enterprise Linux | 2025-05-04 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: x86/hyperv: fix kexec crash due to VP assist page corruption commit 9636be85cc5b ("x86/hyperv: Fix hyperv_pcpu_input_arg handling when CPUs go online/offline") introduces a new cpuhp state for hyperv initialization. cpuhp_setup_state() returns the state number if state is CPUHP_AP_ONLINE_DYN or CPUHP_BP_PREPARE_DYN and 0 for all other states. For the hyperv case, since a new cpuhp state was introduced it would return 0. However, in hv_machine_shutdown(), the cpuhp_remove_state() call is conditioned upon "hyperv_init_cpuhp > 0". This will never be true and so hv_cpu_die() won't be called on all CPUs. This means the VP assist page won't be reset. When the kexec kernel tries to setup the VP assist page again, the hypervisor corrupts the memory region of the old VP assist page causing a panic in case the kexec kernel is using that memory elsewhere. This was originally fixed in commit dfe94d4086e4 ("x86/hyperv: Fix kexec panic/hang issues"). Get rid of hyperv_init_cpuhp entirely since we are no longer using a dynamic cpuhp state and use CPUHP_AP_HYPERV_ONLINE directly with cpuhp_remove_state(). | ||||
| CVE-2024-46863 | 1 Linux | 1 Linux Kernel | 2025-05-04 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: ASoC: Intel: soc-acpi-intel-lnl-match: add missing empty item There is no links_num in struct snd_soc_acpi_mach {}, and we test !link->num_adr as a condition to end the loop in hda_sdw_machine_select(). So an empty item in struct snd_soc_acpi_link_adr array is required. | ||||
| CVE-2024-46862 | 1 Linux | 1 Linux Kernel | 2025-05-04 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: ASoC: Intel: soc-acpi-intel-mtl-match: add missing empty item There is no links_num in struct snd_soc_acpi_mach {}, and we test !link->num_adr as a condition to end the loop in hda_sdw_machine_select(). So an empty item in struct snd_soc_acpi_link_adr array is required. | ||||
| CVE-2024-46861 | 1 Linux | 1 Linux Kernel | 2025-05-04 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: usbnet: ipheth: do not stop RX on failing RX callback RX callbacks can fail for multiple reasons: * Payload too short * Payload formatted incorrecly (e.g. bad NCM framing) * Lack of memory None of these should cause the driver to seize up. Make such failures non-critical and continue processing further incoming URBs. | ||||
| CVE-2024-46838 | 1 Linux | 1 Linux Kernel | 2025-05-04 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: userfaultfd: don't BUG_ON() if khugepaged yanks our page table Since khugepaged was changed to allow retracting page tables in file mappings without holding the mmap lock, these BUG_ON()s are wrong - get rid of them. We could also remove the preceding "if (unlikely(...))" block, but then we could reach pte_offset_map_lock() with transhuge pages not just for file mappings but also for anonymous mappings - which would probably be fine but I think is not necessarily expected. | ||||
| CVE-2024-46837 | 1 Linux | 1 Linux Kernel | 2025-05-04 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: drm/panthor: Restrict high priorities on group_create We were allowing any users to create a high priority group without any permission checks. As a result, this was allowing possible denial of service. We now only allow the DRM master or users with the CAP_SYS_NICE capability to set higher priorities than PANTHOR_GROUP_PRIORITY_MEDIUM. As the sole user of that uAPI lives in Mesa and hardcode a value of MEDIUM [1], this should be safe to do. Additionally, as those checks are performed at the ioctl level, panthor_group_create now only check for priority level validity. [1]https://gitlab.freedesktop.org/mesa/mesa/-/blob/f390835074bdf162a63deb0311d1a6de527f9f89/src/gallium/drivers/panfrost/pan_csf.c#L1038 | ||||
| CVE-2024-46834 | 1 Linux | 1 Linux Kernel | 2025-05-04 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: ethtool: fail closed if we can't get max channel used in indirection tables Commit 0d1b7d6c9274 ("bnxt: fix crashes when reducing ring count with active RSS contexts") proves that allowing indirection table to contain channels with out of bounds IDs may lead to crashes. Currently the max channel check in the core gets skipped if driver can't fetch the indirection table or when we can't allocate memory. Both of those conditions should be extremely rare but if they do happen we should try to be safe and fail the channel change. | ||||
| CVE-2024-46827 | 1 Linux | 1 Linux Kernel | 2025-05-04 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: wifi: ath12k: fix firmware crash due to invalid peer nss Currently, if the access point receives an association request containing an Extended HE Capabilities Information Element with an invalid MCS-NSS, it triggers a firmware crash. This issue arises when EHT-PHY capabilities shows support for a bandwidth and MCS-NSS set for that particular bandwidth is filled by zeros and due to this, driver obtains peer_nss as 0 and sending this value to firmware causes crash. Address this issue by implementing a validation step for the peer_nss value before passing it to the firmware. If the value is greater than zero, proceed with forwarding it to the firmware. However, if the value is invalid, reject the association request to prevent potential firmware crashes. Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.0.1-00029-QCAHKSWPL_SILICONZ-1 | ||||
| CVE-2024-46825 | 1 Linux | 1 Linux Kernel | 2025-05-04 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: wifi: iwlwifi: mvm: use IWL_FW_CHECK for link ID check The lookup function iwl_mvm_rcu_fw_link_id_to_link_conf() is normally called with input from the firmware, so it should use IWL_FW_CHECK() instead of WARN_ON(). | ||||
| CVE-2024-46820 | 2 Linux, Redhat | 2 Linux Kernel, Enterprise Linux | 2025-05-04 | 7.8 High |
| In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/vcn: remove irq disabling in vcn 5 suspend We do not directly enable/disable VCN IRQ in vcn 5.0.0. And we do not handle the IRQ state as well. So the calls to disable IRQ and set state are removed. This effectively gets rid of the warining of "WARN_ON(!amdgpu_irq_enabled(adev, src, type))" in amdgpu_irq_put(). | ||||
| CVE-2024-46801 | 1 Linux | 1 Linux Kernel | 2025-05-04 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: libfs: fix get_stashed_dentry() get_stashed_dentry() tries to optimistically retrieve a stashed dentry from a provided location. It needs to ensure to hold rcu lock before it dereference the stashed location to prevent UAF issues. Use rcu_dereference() instead of READ_ONCE() it's effectively equivalent with some lockdep bells and whistles and it communicates clearly that this expects rcu protection. | ||||
| CVE-2024-46792 | 1 Linux | 1 Linux Kernel | 2025-05-04 | 3.3 Low |
| In the Linux kernel, the following vulnerability has been resolved: riscv: misaligned: Restrict user access to kernel memory raw_copy_{to,from}_user() do not call access_ok(), so this code allowed userspace to access any virtual memory address. | ||||
| CVE-2024-46790 | 1 Linux | 1 Linux Kernel | 2025-05-04 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: codetag: debug: mark codetags for poisoned page as empty When PG_hwpoison pages are freed they are treated differently in free_pages_prepare() and instead of being released they are isolated. Page allocation tag counters are decremented at this point since the page is considered not in use. Later on when such pages are released by unpoison_memory(), the allocation tag counters will be decremented again and the following warning gets reported: [ 113.930443][ T3282] ------------[ cut here ]------------ [ 113.931105][ T3282] alloc_tag was not set [ 113.931576][ T3282] WARNING: CPU: 2 PID: 3282 at ./include/linux/alloc_tag.h:130 pgalloc_tag_sub.part.66+0x154/0x164 [ 113.932866][ T3282] Modules linked in: hwpoison_inject fuse ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 ipt_REJECT nf_reject_ipv4 xt_conntrack ebtable_nat ebtable_broute ip6table_nat ip6table_man4 [ 113.941638][ T3282] CPU: 2 UID: 0 PID: 3282 Comm: madvise11 Kdump: loaded Tainted: G W 6.11.0-rc4-dirty #18 [ 113.943003][ T3282] Tainted: [W]=WARN [ 113.943453][ T3282] Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022 [ 113.944378][ T3282] pstate: 40400005 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 113.945319][ T3282] pc : pgalloc_tag_sub.part.66+0x154/0x164 [ 113.946016][ T3282] lr : pgalloc_tag_sub.part.66+0x154/0x164 [ 113.946706][ T3282] sp : ffff800087093a10 [ 113.947197][ T3282] x29: ffff800087093a10 x28: ffff0000d7a9d400 x27: ffff80008249f0a0 [ 113.948165][ T3282] x26: 0000000000000000 x25: ffff80008249f2b0 x24: 0000000000000000 [ 113.949134][ T3282] x23: 0000000000000001 x22: 0000000000000001 x21: 0000000000000000 [ 113.950597][ T3282] x20: ffff0000c08fcad8 x19: ffff80008251e000 x18: ffffffffffffffff [ 113.952207][ T3282] x17: 0000000000000000 x16: 0000000000000000 x15: ffff800081746210 [ 113.953161][ T3282] x14: 0000000000000000 x13: 205d323832335420 x12: 5b5d353031313339 [ 113.954120][ T3282] x11: ffff800087093500 x10: 000000000000005d x9 : 00000000ffffffd0 [ 113.955078][ T3282] x8 : 7f7f7f7f7f7f7f7f x7 : ffff80008236ba90 x6 : c0000000ffff7fff [ 113.956036][ T3282] x5 : ffff000b34bf4dc8 x4 : ffff8000820aba90 x3 : 0000000000000001 [ 113.956994][ T3282] x2 : ffff800ab320f000 x1 : 841d1e35ac932e00 x0 : 0000000000000000 [ 113.957962][ T3282] Call trace: [ 113.958350][ T3282] pgalloc_tag_sub.part.66+0x154/0x164 [ 113.959000][ T3282] pgalloc_tag_sub+0x14/0x1c [ 113.959539][ T3282] free_unref_page+0xf4/0x4b8 [ 113.960096][ T3282] __folio_put+0xd4/0x120 [ 113.960614][ T3282] folio_put+0x24/0x50 [ 113.961103][ T3282] unpoison_memory+0x4f0/0x5b0 [ 113.961678][ T3282] hwpoison_unpoison+0x30/0x48 [hwpoison_inject] [ 113.962436][ T3282] simple_attr_write_xsigned.isra.34+0xec/0x1cc [ 113.963183][ T3282] simple_attr_write+0x38/0x48 [ 113.963750][ T3282] debugfs_attr_write+0x54/0x80 [ 113.964330][ T3282] full_proxy_write+0x68/0x98 [ 113.964880][ T3282] vfs_write+0xdc/0x4d0 [ 113.965372][ T3282] ksys_write+0x78/0x100 [ 113.965875][ T3282] __arm64_sys_write+0x24/0x30 [ 113.966440][ T3282] invoke_syscall+0x7c/0x104 [ 113.966984][ T3282] el0_svc_common.constprop.1+0x88/0x104 [ 113.967652][ T3282] do_el0_svc+0x2c/0x38 [ 113.968893][ T3282] el0_svc+0x3c/0x1b8 [ 113.969379][ T3282] el0t_64_sync_handler+0x98/0xbc [ 113.969980][ T3282] el0t_64_sync+0x19c/0x1a0 [ 113.970511][ T3282] ---[ end trace 0000000000000000 ]--- To fix this, clear the page tag reference after the page got isolated and accounted for. | ||||
| CVE-2024-46789 | 1 Linux | 1 Linux Kernel | 2025-05-04 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: mm/slub: add check for s->flags in the alloc_tagging_slab_free_hook When enable CONFIG_MEMCG & CONFIG_KFENCE & CONFIG_KMEMLEAK, the following warning always occurs,This is because the following call stack occurred: mem_pool_alloc kmem_cache_alloc_noprof slab_alloc_node kfence_alloc Once the kfence allocation is successful,slab->obj_exts will not be empty, because it has already been assigned a value in kfence_init_pool. Since in the prepare_slab_obj_exts_hook function,we perform a check for s->flags & (SLAB_NO_OBJ_EXT | SLAB_NOLEAKTRACE),the alloc_tag_add function will not be called as a result.Therefore,ref->ct remains NULL. However,when we call mem_pool_free,since obj_ext is not empty, it eventually leads to the alloc_tag_sub scenario being invoked. This is where the warning occurs. So we should add corresponding checks in the alloc_tagging_slab_free_hook. For __GFP_NO_OBJ_EXT case,I didn't see the specific case where it's using kfence,so I won't add the corresponding check in alloc_tagging_slab_free_hook for now. [ 3.734349] ------------[ cut here ]------------ [ 3.734807] alloc_tag was not set [ 3.735129] WARNING: CPU: 4 PID: 40 at ./include/linux/alloc_tag.h:130 kmem_cache_free+0x444/0x574 [ 3.735866] Modules linked in: autofs4 [ 3.736211] CPU: 4 UID: 0 PID: 40 Comm: ksoftirqd/4 Tainted: G W 6.11.0-rc3-dirty #1 [ 3.736969] Tainted: [W]=WARN [ 3.737258] Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022 [ 3.737875] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 3.738501] pc : kmem_cache_free+0x444/0x574 [ 3.738951] lr : kmem_cache_free+0x444/0x574 [ 3.739361] sp : ffff80008357bb60 [ 3.739693] x29: ffff80008357bb70 x28: 0000000000000000 x27: 0000000000000000 [ 3.740338] x26: ffff80008207f000 x25: ffff000b2eb2fd60 x24: ffff0000c0005700 [ 3.740982] x23: ffff8000804229e4 x22: ffff800082080000 x21: ffff800081756000 [ 3.741630] x20: fffffd7ff8253360 x19: 00000000000000a8 x18: ffffffffffffffff [ 3.742274] x17: ffff800ab327f000 x16: ffff800083398000 x15: ffff800081756df0 [ 3.742919] x14: 0000000000000000 x13: 205d344320202020 x12: 5b5d373038343337 [ 3.743560] x11: ffff80008357b650 x10: 000000000000005d x9 : 00000000ffffffd0 [ 3.744231] x8 : 7f7f7f7f7f7f7f7f x7 : ffff80008237bad0 x6 : c0000000ffff7fff [ 3.744907] x5 : ffff80008237ba78 x4 : ffff8000820bbad0 x3 : 0000000000000001 [ 3.745580] x2 : 68d66547c09f7800 x1 : 68d66547c09f7800 x0 : 0000000000000000 [ 3.746255] Call trace: [ 3.746530] kmem_cache_free+0x444/0x574 [ 3.746931] mem_pool_free+0x44/0xf4 [ 3.747306] free_object_rcu+0xc8/0xdc [ 3.747693] rcu_do_batch+0x234/0x8a4 [ 3.748075] rcu_core+0x230/0x3e4 [ 3.748424] rcu_core_si+0x14/0x1c [ 3.748780] handle_softirqs+0x134/0x378 [ 3.749189] run_ksoftirqd+0x70/0x9c [ 3.749560] smpboot_thread_fn+0x148/0x22c [ 3.749978] kthread+0x10c/0x118 [ 3.750323] ret_from_fork+0x10/0x20 [ 3.750696] ---[ end trace 0000000000000000 ]--- | ||||
| CVE-2024-46787 | 2 Linux, Redhat | 2 Linux Kernel, Enterprise Linux | 2025-05-04 | 4.7 Medium |
| In the Linux kernel, the following vulnerability has been resolved: userfaultfd: fix checks for huge PMDs Patch series "userfaultfd: fix races around pmd_trans_huge() check", v2. The pmd_trans_huge() code in mfill_atomic() is wrong in three different ways depending on kernel version: 1. The pmd_trans_huge() check is racy and can lead to a BUG_ON() (if you hit the right two race windows) - I've tested this in a kernel build with some extra mdelay() calls. See the commit message for a description of the race scenario. On older kernels (before 6.5), I think the same bug can even theoretically lead to accessing transhuge page contents as a page table if you hit the right 5 narrow race windows (I haven't tested this case). 2. As pointed out by Qi Zheng, pmd_trans_huge() is not sufficient for detecting PMDs that don't point to page tables. On older kernels (before 6.5), you'd just have to win a single fairly wide race to hit this. I've tested this on 6.1 stable by racing migration (with a mdelay() patched into try_to_migrate()) against UFFDIO_ZEROPAGE - on my x86 VM, that causes a kernel oops in ptlock_ptr(). 3. On newer kernels (>=6.5), for shmem mappings, khugepaged is allowed to yank page tables out from under us (though I haven't tested that), so I think the BUG_ON() checks in mfill_atomic() are just wrong. I decided to write two separate fixes for these (one fix for bugs 1+2, one fix for bug 3), so that the first fix can be backported to kernels affected by bugs 1+2. This patch (of 2): This fixes two issues. I discovered that the following race can occur: mfill_atomic other thread ============ ============ <zap PMD> pmdp_get_lockless() [reads none pmd] <bail if trans_huge> <if none:> <pagefault creates transhuge zeropage> __pte_alloc [no-op] <zap PMD> <bail if pmd_trans_huge(*dst_pmd)> BUG_ON(pmd_none(*dst_pmd)) I have experimentally verified this in a kernel with extra mdelay() calls; the BUG_ON(pmd_none(*dst_pmd)) triggers. On kernels newer than commit 0d940a9b270b ("mm/pgtable: allow pte_offset_map[_lock]() to fail"), this can't lead to anything worse than a BUG_ON(), since the page table access helpers are actually designed to deal with page tables concurrently disappearing; but on older kernels (<=6.4), I think we could probably theoretically race past the two BUG_ON() checks and end up treating a hugepage as a page table. The second issue is that, as Qi Zheng pointed out, there are other types of huge PMDs that pmd_trans_huge() can't catch: devmap PMDs and swap PMDs (in particular, migration PMDs). On <=6.4, this is worse than the first issue: If mfill_atomic() runs on a PMD that contains a migration entry (which just requires winning a single, fairly wide race), it will pass the PMD to pte_offset_map_lock(), which assumes that the PMD points to a page table. Breakage follows: First, the kernel tries to take the PTE lock (which will crash or maybe worse if there is no "struct page" for the address bits in the migration entry PMD - I think at least on X86 there usually is no corresponding "struct page" thanks to the PTE inversion mitigation, amd64 looks different). If that didn't crash, the kernel would next try to write a PTE into what it wrongly thinks is a page table. As part of fixing these issues, get rid of the check for pmd_trans_huge() before __pte_alloc() - that's redundant, we're going to have to check for that after the __pte_alloc() anyway. Backport note: pmdp_get_lockless() is pmd_read_atomic() in older kernels. | ||||