Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: erofs: fix the out-of-bounds nameoff handling for trailing dirents Currently we already have boundary-checks for nameoffs, but the trailing dirents are special since the namelens are calculated with strnlen() with unchecked nameoffs. If a crafted EROFS has a trailing dirent with nameoff >= maxsize, maxsize - nameoff can underflow, causing strnlen() to read past the directory block. nameoff0 should also be verified to be a multiple of `sizeof(struct erofs_dirent)` as well [1]. [1] https://sashiko.dev/#/patchset/20260416063511.3173774-1-hsiangkao%40linux.alibaba.comShow less

In the Linux kernel, the following vulnerability has been resolved: crypto: atmel-tdes - fix DMA sync direction Before DMA output is consumed by the CPU, ->dma_addr_out must be synced with dma_sync_single_for_cpu() instead of dma_sync_single_for_device(). Using the wrong direction can return stale cache data on non-coherent platforms.Show less

In the Linux kernel, the following vulnerability has been resolved: KVM: nSVM: Raise #UD if unhandled VMMCALL isn't intercepted by L1 Explicitly synthesize a #UD for VMMCALL if L2 is active, L1 does NOT want to intercept VMMCALL, nested_svm_l2_tlb_flush_enabled() is true, and the hypercall is something other than one of the supported Hyper-V hypercalls. When all of the above conditions are met, KVM will intercept VMMCALL but never forward it to L1, i.e. will let L2 make hypercalls as if it were L1. The TLFS says a whole lot of nothing about this scenario, so go with the architectural behavior, which says that VMMCALL #UDs if it's not intercepted. Opportunistically do a 2-for-1 stub trade by stub-ifying the new API instead of the helpers it uses. The last remaining "single" stub will soon be dropped as well. [sean: rewrite changelog and comment, tag for stable, remove defunct stubs]Show less

In the Linux kernel, the following vulnerability has been resolved: crypto: atmel-sha204a - Fix potential UAF and memory leak in remove path Unregister the hwrng to prevent new ->read() calls and flush the Atmel I2C workqueue before teardown to prevent a potential UAF if a queued callback runs while the device is being removed. Drop the early return to ensure sysfs entries are removed and ->hwrng.priv is freed, preventing a memory leak.Show less

In the Linux kernel, the following vulnerability has been resolved: spi: ch341: fix memory leaks on probe failures Make sure to deregister the controller, disable pins, and kill and free the RX URB on probe failures to mirror disconnect and avoid memory leaks and use-after-free. Also add an explicit URB kill on disconnect for symmetry (even if that is not strictly required as USB core would have stopped it in the current setup).Show less

In the Linux kernel, the following vulnerability has been resolved: hwmon: (powerz) Fix missing usb_kill_urb() on signal interrupt wait_for_completion_interruptible_timeout() returns -ERESTARTSYS when interrupted. This needs to abort the URB and return an error. No data has been received from the device so any reads from the transfer buffer are invalid. The original code tests !ret, which only catches the timeout case (0). On signal delivery (-ERESTARTSYS), !ret is false so the function skips usb_kill_urb() and falls through to read from the unfilled transfer buffer. Fix by capturing the return value into a long (matching the function return type) and handling signal (negative) and timeout (zero) cases with separate checks that both call usb_kill_urb() before returning.Show less

In the Linux kernel, the following vulnerability has been resolved: ntfs3: add buffer boundary checks to run_unpack() run_unpack() checks `run_buf < run_last` at the top of the while loop but then reads size_size and offset_size bytes via run_unpack_s64() without verifying they fit within the remaining buffer. A crafted NTFS image with truncated run data in an MFT attribute triggers an OOB heap read of up to 15 bytes when the filesystem is mounted. Add boundary checks before each run_unpack_s64() call to ensure the declared field size does not exceed the remaining buffer. Found by fuzzing with a source-patched harness (LibAFL + QEMU).Show less

In the Linux kernel, the following vulnerability has been resolved: KVM: nSVM: Avoid clearing VMCB_LBR in vmcb12 svm_copy_lbrs() always marks VMCB_LBR dirty in the destination VMCB. However, nested_svm_vmexit() uses it to copy LBRs to vmcb12, and clearing clean bits in vmcb12 is not architecturally defined. Move vmcb_mark_dirty() to callers and drop it for vmcb12. This also facilitates incoming refactoring that does not pass the entire VMCB to svm_copy_lbrs().Show less

In the Linux kernel, the following vulnerability has been resolved: md/raid5: validate payload size before accessing journal metadata r5c_recovery_analyze_meta_block() and r5l_recovery_verify_data_checksum_for_mb() iterate over payloads in a journal metadata block using on-disk payload size fields without validating them against the remaining space in the metadata block. A corrupted journal contains payload sizes extending beyond the PAGE_SIZE boundary can cause out-of-bounds reads when accessing payload fields or computing offsets. Add bounds validation for each payload type to ensure the full payload fits within meta_size before processing.Show less

In the Linux kernel, the following vulnerability has been resolved: wifi: mwifiex: fix use-after-free in mwifiex_adapter_cleanup() The mwifiex_adapter_cleanup() function uses timer_delete() (non-synchronous) for the wakeup_timer before the adapter structure is freed. This is incorrect because timer_delete() does not wait for any running timer callback to complete. If the wakeup_timer callback (wakeup_timer_fn) is executing when mwifiex_adapter_cleanup() is called, the callback will continue to access adapter fields (adapter->hw_status, adapter->if_ops.card_reset, etc.) which may be freed by mwifiex_free_adapter() called later in the mwifiex_remove_card() path. Use timer_delete_sync() instead to ensure any running timer callback has completed before returning.Show less

In the Linux kernel, the following vulnerability has been resolved: crypto: nx - fix bounce buffer leaks in nx842_crypto_{alloc,free}_ctx The bounce buffers are allocated with __get_free_pages() using BOUNCE_BUFFER_ORDER (order 2 = 4 pages), but both the allocation error path and nx842_crypto_free_ctx() release the buffers with free_page(). Use free_pages() with the matching order instead.Show less

In the Linux kernel, the following vulnerability has been resolved: mm/damon/core: validate damos_quota_goal->nid for node_memcg_{used,free}_bp Users can set damos_quota_goal->nid with arbitrary value for node_memcg_{used,free}_bp. But DAMON core is using those for NODE-DATA() without a validation of the value. This can result in out of bounds memory access. The issue can actually triggered using DAMON user-space tool (damo), like below. $ sudo mkdir /sys/fs/cgroup/foo $ sudo ./damo start --damos_action stat --damos_quota_interval 1s \ --damos_quota_goal node_memcg_used_bp 50% -1 /foo $ sudo dmseg [...] [ 524.181426] Unable to handle kernel paging request at virtual address 0000000000002c00 Fix this issue by adding the validation of the given node id. If an invalid node id is given, it returns 0% for used memory ratio, and 100% for free memory ratio.Show less

In the Linux kernel, the following vulnerability has been resolved: ceph: fix num_ops off-by-one when crypto allocation fails move_dirty_folio_in_page_array() may fail if the file is encrypted, the dirty folio is not the first in the batch, and it fails to allocate a bounce buffer to hold the ciphertext. When that happens, ceph_process_folio_batch() simply redirties the folio and flushes the current batch -- it can retry that folio in a future batch. However, if this failed folio is not contiguous with the last folio that did make it into the batch, then ceph_process_folio_batch() has already incremented `ceph_wbc->num_ops`; because it doesn't follow through and add the discontiguous folio to the array, ceph_submit_write() -- which expects that `ceph_wbc->num_ops` accurately reflects the number of contiguous ranges (and therefore the required number of "write extent" ops) in the writeback -- will panic the kernel: BUG_ON(ceph_wbc->op_idx + 1 != req->r_num_ops); This issue can be reproduced on affected kernels by writing to fscrypt-enabled CephFS file(s) with a 4KiB-written/4KiB-skipped/repeat pattern (total filesize should not matter) and gradually increasing the system's memory pressure until a bounce buffer allocation fails. Fix this crash by decrementing `ceph_wbc->num_ops` back to the correct value when move_dirty_folio_in_page_array() fails, but the folio already started counting a new (i.e. still-empty) extent. The defect corrected by this patch has existed since 2022 (see first `Fixes:`), but another bug blocked multi-folio encrypted writeback until recently (see second `Fixes:`). The second commit made it into 6.18.16, 6.19.6, and 7.0-rc1, unmasking the panic in those versions. This patch therefore fixes a regression (panic) introduced by cac190c7674f.Show less

In the Linux kernel, the following vulnerability has been resolved: fbdev: defio: Disconnect deferred I/O from the lifetime of struct fb_info Hold state of deferred I/O in struct fb_deferred_io_state. Allocate an instance as part of initializing deferred I/O and remove it only after the final mapping has been closed. If the fb_info and the contained deferred I/O meanwhile goes away, clear struct fb_deferred_io_state.info to invalidate the mapping. Any access will then result in a SIGBUS signal. Fixes a long-standing problem, where a device hot-unplug happens while user space still has an active mapping of the graphics memory. The hot- unplug frees the instance of struct fb_info. Accessing the memory will operate on undefined state.Show less

In the Linux kernel, the following vulnerability has been resolved: ibmasm: fix heap over-read in ibmasm_send_i2o_message() The ibmasm_send_i2o_message() function uses get_dot_command_size() to compute the byte count for memcpy_toio(), but this value is derived from user-controlled fields in the dot_command_header (command_size: u8, data_size: u16) and is never validated against the actual allocation size. A root user can write a small buffer with inflated header fields, causing memcpy_toio() to read up to ~65 KB past the end of the allocation into adjacent kernel heap, which is then forwarded to the service processor over MMIO. Silently clamping the copy size is not sufficient: if the header fields claim a larger size than the buffer, the SP receives a dot command whose own header is inconsistent with the I2O message length, which can cause the SP to desynchronize. Reject such commands outright by returning failure. Validate command_size before calling get_mfa_inbound() to avoid leaking an I2O message frame: reading INBOUND_QUEUE_PORT dequeues a hardware frame from the controller's free pool, and returning without a corresponding set_mfa_inbound() call would permanently exhaust it. Additionally, clamp command_size to I2O_COMMAND_SIZE before the memcpy_toio() so the MMIO write stays within the I2O message frame, consistent with the clamping already performed by outgoing_message_size() for the header field.Show less

In the Linux kernel, the following vulnerability has been resolved: x86/shstk: Prevent deadlock during shstk sigreturn During sigreturn the shadow stack signal frame is popped. The kernel does this by reading the shadow stack using normal read accesses. When it can't assume the memory is shadow stack, it takes extra steps to makes sure it is reading actual shadow stack memory and not other normal readable memory. It does this by holding the mmap read lock while doing the access and checking the flags of the VMA. Unfortunately that is not safe. If the read of the shadow stack sigframe hits a page fault, the fault handler will try to recursively grab another mmap read lock. This normally works ok, but if a writer on another CPU is also waiting, the second read lock could fail and cause a deadlock. Fix this by not holding mmap lock during the read access to userspace. Instead use mmap_lock_speculate_...() to watch for changes between dropping mmap lock and the userspace access. Retry if anything grabbed an mmap write lock in between and could have changed the VMA. These mmap_lock_speculate_...() helpers use mm::mm_lock_seq, which is only available when PER_VMA_LOCK is configured. So make X86_USER_SHADOW_STACK depend on it. On x86, PER_VMA_LOCK is a default configuration for SMP kernels. So drop support for the other configs under the assumption that the !SMP shadow stack user base does not exist. Currently there is a check that skips the lookup work when the SSP can be assumed to be on a shadow stack. While reorganizing the function, remove the optimization to make the tricky code flows more common, such that issues like this cannot escape detection for so long.Show less

In the Linux kernel, the following vulnerability has been resolved: ntfs3: fix integer overflow in run_unpack() volume boundary check The volume boundary check `lcn + len > sbi->used.bitmap.nbits` uses raw addition which can wrap around for large lcn and len values, bypassing the validation. Use check_add_overflow() as is already done for the adjacent prev_lcn + dlcn and vcn64 + len checks added by commit 3ac37e100385 ("ntfs3: Fix integer overflow in run_unpack()"). Found by fuzzing with a source-patched harness (LibAFL + QEMU).Show less

In the Linux kernel, the following vulnerability has been resolved: jbd2: fix deadlock in jbd2_journal_cancel_revoke() Commit f76d4c28a46a ("fs/jbd2: use sleeping version of __find_get_block()") changed jbd2_journal_cancel_revoke() to use __find_get_block_nonatomic() which holds the folio lock instead of i_private_lock. This breaks the lock ordering (folio -> buffer) and causes an ABBA deadlock when the filesystem blocksize < pagesize: T1 T2 ext4_mkdir() ext4_init_new_dir() ext4_append() ext4_getblk() lock_buffer() <- A sync_blockdev() blkdev_writepages() writeback_iter() writeback_get_folio() folio_lock() <- B ext4_journal_get_create_access() jbd2_journal_cancel_revoke() __find_get_block_nonatomic() folio_lock() <- B block_write_full_folio() lock_buffer() <- A This can occasionally cause generic/013 to hang. Fix by only calling __find_get_block_nonatomic() when the passed buffer_head doesn't belong to the bdev, which is the only case that we need to look up its bdev alias. Otherwise, the lookup is redundant since the found buffer_head is equal to the one we passed in.Show less

In the Linux kernel, the following vulnerability has been resolved: crypto: qat - fix IRQ cleanup on 6xxx probe failure When adf_dev_up() partially completes and then fails, the IRQ handlers registered during adf_isr_resource_alloc() are not detached before the MSI-X vectors are released. Since the device is enabled with pcim_enable_device(), calling pci_alloc_irq_vectors() internally registers pcim_msi_release() as a devres action. On probe failure, devres runs pcim_msi_release() which calls pci_free_irq_vectors(), tearing down the MSI-X vectors while IRQ handlers (for example 'qat0-bundle0') are still attached. This causes remove_proc_entry() warnings: [ 22.163964] remove_proc_entry: removing non-empty directory 'irq/143', leaking at least 'qat0-bundle0' Moving the devm_add_action_or_reset() before adf_dev_up() does not solve the problem since devres runs in LIFO order and pcim_msi_release(), registered later inside adf_dev_up(), would still fire before adf_device_down(). Fix by calling adf_dev_down() explicitly when adf_dev_up() fails, to properly free IRQ handlers before devres releases the MSI-X vectors.Show less

In the Linux kernel, the following vulnerability has been resolved: KVM: nSVM: Always use NextRIP as vmcb02's NextRIP after first L2 VMRUN For guests with NRIPS disabled, L1 does not provide NextRIP when running an L2 with an injected soft interrupt, instead it advances the current RIP before running it. KVM uses the current RIP as the NextRIP in vmcb02 to emulate a CPU without NRIPS. However, after L2 runs the first time, NextRIP will be updated by the CPU and/or KVM, and the current RIP is no longer the correct value to use in vmcb02. Hence, after save/restore, use the current RIP if and only if a nested run is pending, otherwise use NextRIP. Give soft_int_next_rip the same treatment, as it's the same logic, just for a narrower use case. [sean: give soft_int_next_rip the same treatment]Show less