Linux Linux Kernel vulnerabilities

In the Linux kernel, the following vulnerability has been resolved: KVM: x86/mmu: Check write tracking in all address spaces kvm_gfn_is_write_tracked() checks only the supplied memslot, but page tracking is per-address-space and shadow pages are shared across all address spaces. With SMM, a GFN can therefore be write-tracked in one address space and appear untracked through the other. Check the supplied slot first, then the slot for the other address space. This ensures all callers honor write tracking regardless of the active address space. In particular, it prevents mmu_try_to_unsync_pages() from marking an upper-level shadow page unsync and eventually triggering the BUG in pte_list_remove(). [invert direction of the conditional. - Paolo]

In the Linux kernel, the following vulnerability has been resolved: smb/server: fix tree connection leak in smb2_tree_connect() See the procedure below: smb2_tree_connect ksmbd_tree_conn_connect xa_store(&sess->tree_conns, tree_conn->id, tree_conn) ksmbd_counter_inc(KSMBD_COUNTER_TREE_CONNS) ksmbd_share_tree_conn_inc(sc) ksmbd_iov_pin_rsp // fail status.ret = KSMBD_TREE_CONN_STATUS_NOMEM // do not disconnect tree_conn Disconnect the new tree connection if ksmbd_iov_pin_rsp() fails.

In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: mt7921: validate CLC firmware records The CLC region is supplied by firmware, but the loader trusts the region count and each record length. A malformed image can make the region table pointer precede the firmware buffer, make the record loop fail to advance, or index phy->clc past its end. Validate the table and record bounds before dereferencing or copying.

In the Linux kernel, the following vulnerability has been resolved: ntfs: only count successfully cleared runs when freeing clusters ntfs_cluster_free_from_rl_nolock() adds a run's length to nr_freed whenever the error bookkeeping condition is false, which includes cases where ntfs_bitmap_clear_run() actually failed - e.g. a second run failing with the same errno as an earlier one, or any failure after a non-ENOMEM error was already recorded. Since a failed ntfs_bitmap_clear_run() rolls back its partial modifications, no bits were cleared for that run, yet its length still inflates vol->free_clusters, corrupting statfs output and the allocator's free space gate. Only count runs whose bitmap clear succeeded.

In the Linux kernel, the following vulnerability has been resolved: ntfs: do not mark the volume clean in sync_fs when errors were recorded ntfs_put_super() and the remount-read-only path both clear the dirty bit only when NVolErrors(vol) is false. ntfs_sync_fs() clears it unconditionally, so any sync() on a volume that recorded an error marks that volume clean. A volume without this set is then seen as not needing recovery and it does not run one, so whatever went wrong is never repaired. This change skips resetting the dirty bit when there are volume errors. Reproduced on a volume whose $MFTMirr does not match $MFT, which sets the error flag while leaving the mount read-write: after a write and a sync, the on-disk volume flags read 0x0000 with this driver and 0x0001 with the guard in place.

In the Linux kernel, the following vulnerability has been resolved: ntfs: treat any nonzero dio zero-range return as an error ntfs_dio_zero_range() returns either 0 or a negative errno from blkdev_issue_zeroout(); it never returns a positive value. The zeroing failure check in ntfs_attr_fallocate() therefore never fired, so a failed zeroing operation was silently ignored: the loop kept going, the newly allocated clusters were folded into initialized_size and the write could succeed leaving stale on-disk data. Treat any nonzero return as an error and abort the allocation.

In the Linux kernel, the following vulnerability has been resolved: ntfs: reject invalid sectors_per_cluster in the boot sector is_boot_sector_ntfs() checks the boot sector's sectors_per_cluster field with a range test that rejects 0x81..0xf3 but accepts 0 and other non-power-of-two counts. A zero value reaches parse_ntfs_boot_sector(): sectors_per_cluster_bits = ffs(sectors_per_cluster) - 1; ... vol->cluster_size = vol->sector_size << sectors_per_cluster_bits; ffs(0) is 0, so sectors_per_cluster_bits becomes (unsigned)-1 and the shift is undefined: UBSAN: shift-out-of-bounds in fs/ntfs/super.c:673:39 shift exponent 4294967295 is too large for 32-bit type 'int' This change rejects any non-power-of-two value, since it feeds the aforementioned shift via ffs() - 1, which only yields the correct shift for a power of two.

In the Linux kernel, the following vulnerability has been resolved: bpf: check_cond_jmp_op(): properly infer if register is null Nicholas Carlini reported a bug when verifier can incorrectly infer that a pointer is non-null. The bug occurs when two pointers are compared and one of them has a type w/o PTR_MAYBE_NULL flag, but which allows a value to be NULL at runtime. Here is an example: // `a` is PTR_TO_MEM | MEM_RDONLY | PTR_UNTRUSTED // `a` is 0 at runtime. // `b` is PTR_TO_MAP_VALUE | PTR_MAYBE_NULL void *a = bpf_rdonly_cast(0, 0); int *b = bpf_map_lookup_elem(...); if (a == b) *b = 42; // verifier does not catch null pointer dereference This happens because of a special case in check_cond_jmp_op(), which attempts to strip PTR_MAYBE_NULL flags from pointer types, when processing comparisons like `rA == rB`, if either rA or rB can't be null. The non-null property is derived based on the absence of PTR_MAYBE_NULL flag on rA's or rB's type. But that is not sufficient for types like PTR_TO_MEM, as in the example. This patch replaces type_may_be_null() call with reg_not_null(), which contains an allowlist of types for which absence of PTR_MAYBE_NULL actually means that the value can't be NULL at runtime. At the moment, the list in the reg_not_null() omits two types for which PTR_MAYBE_NULL is applicable: PTR_TO_XDP_SOCK and PTR_TO_BUF. In order to remain backward compatible, and assuming that only comparison between pointers of the same type makes sense, this commit extends reg_not_null(). W/o such an extension e.g. verifier_jeq_infer_not_null/null_ptr_to_map_value fails. reg_not_null() can be extended further, but I deem that out of scope for the fix at hand. Explicit base_type(...) != PTR_TO_BTF_ID checks in the check_cond_jmp_op() can be removed with migration to reg_not_null(), but that is a behavioural change, as the special case would start matching for PTR_TO_BTF_ID that is also is_trusted_reg(). I omit the behavioural change from this commit.

In the Linux kernel, the following vulnerability has been resolved: ntfs: leave HasEA flag untouched on setxattr failure In ntfs_set_ea(), the exit path unconditionally updates the HasEA flag based on ea_info_qsize. When an error occurs before ea_info_qsize is updated, NInoClearHasEA() hides existing on-disk EAs until the inode is evicted. Only update the flag on success.

In the Linux kernel, the following vulnerability has been resolved: bpf: don't downgrade half-dead scalar zero spills to STACK_ZERO states.c:__clean_func_state() can downgrade scalar zero spill to STACK_ZERO in the following case: *(u64 *)(r10 - 8) = 0; ... checkpoint ... r1 = *(u32 *)(r10 - 4); ... no reads from r10-8 ... Here 4 bytes at r10-8 are dead and verifier changes scalar spill to a combination: 0000pppp (p stands for poison). Such a change breaks precision propagation chains. All places that produce STACK_ZERO should call bpf_mark_chain_precision() for the zero source. This patch fixes the bug in a simplest way possible: avoids converting stack spills of zero to STACK_ZERO. Two smarter approaches are possible: - do bpf_mark_chain_precision() from __clean_func_state() - check slot liveness information in check_stack_write_fixed_off() I investigated both and the changes required are a bit tricky, hence go with a simple fix for the time being.

In the Linux kernel, the following vulnerability has been resolved: net: stmmac: fix dma mapping leak in stmmac_tso_xmit() In stmmac_tso_xmit(), if the DMA mapping of an skb fragment fails, the frame is dropped but the DMA mappings already created for the linear part and for the fragments mapped before the failure are never unmapped, leaking DMA mappings. Fix the leak by walking back over the descriptors used by the frame and releasing each of them with stmmac_free_tx_buffer(). Moreover, release the descriptors with stmmac_release_tx_desc() unmapping the DMA buffers.

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix the possible bioc_list memory leak during error There are two possible ways to leak bioc memory on btrfs_ordered_extent::bioc_list: - An error occurred for btrfs_insert_one_raid_extent() Then the function btrfs_insert_raid_extent() immediately return without freeing any bioc in the bioc_list. - An ordered extent hit an IO error In that case the ordered extent will have BTRFS_ORDERED_IOERR set, and skip the call on btrfs_insert_raid_extent() completely. Fix the problem by: - Introduce a new helper, btrfs_cleanup_ordered_bioc_list() Which will remove all bioc from the bioc_list, and release the bioc. - Call the above helper for btrfs_insert_raid_extent() So that the cleanup helper is always called no matter what. - Call the above helper for btrfs_finish_one_ordered() This is called just before the final release on the ordered extent. This was reported by Sashiko when reviewing another patch.

In the Linux kernel, the following vulnerability has been resolved: btrfs: do not force reloc root creation during qgroup_account_snapshot() [BUG] When running btrfs/252 with quota enabled through MKFS_OPTIONS="-O quota", it has a high chance to trigger the following kernel warning and flips the fs RO: BTRFS info (device dm-2): relocating block group 30408704 flags metadata|dup ------------[ cut here ]------------ WARNING: fs/btrfs/extent-tree.c:879 at lookup_inline_extent_backref+0x74b/0x960 [btrfs], CPU#4: btrfs/2173 CPU: 4 UID: 0 PID: 2173 Comm: btrfs Not tainted 7.2.0-rc6-custom+ #457 PREEMPT(full) 3adc6528fb66f7a55fe1095385818e742f200aab Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022 RIP: 0010:lookup_inline_extent_backref+0x74b/0x960 [btrfs] Call Trace: <TASK> insert_inline_extent_backref+0x7c/0x160 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] __btrfs_inc_extent_ref+0xa9/0x270 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] __btrfs_run_delayed_refs+0x4af/0x11c0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] btrfs_run_delayed_refs+0x9d/0xf0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] create_pending_snapshot+0x39d/0xf00 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] create_pending_snapshots+0x9b/0xc0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] btrfs_commit_transaction+0x280/0xeb0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] prepare_to_relocate+0x147/0x200 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] relocate_block_group+0x6b/0x5e0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] btrfs_relocate_block_group+0x92c/0x2380 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] btrfs_relocate_chunk+0x3f/0x1a0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] btrfs_balance+0xa2c/0x19c0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] btrfs_ioctl+0x2839/0x2d30 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] __x64_sys_ioctl+0x416/0x9a0 do_syscall_64+0xe1/0x790 entry_SYSCALL_64_after_hwframe+0x4b/0x53 </TASK> ---[ end trace 0000000000000000 ]--- BTRFS info (device dm-2): leaf 4593991680 gen 233 total ptrs 175 free space 5953 owner 2 BTRFS info (device dm-2): refs 3 lock_owner 2173 current 2173 item 0 key (166772736 METADATA_ITEM 1) itemoff 16250 itemsize 33 extent refs 1 gen 222 flags 2 ref#0: tree block backref root 266 [ Skip the tree dump ] item 174 key (263225344 METADATA_ITEM 0) itemoff 10328 itemsize 33 extent refs 1 gen 162 flags 258 ref#0: tree block backref root 267 BTRFS error (device dm-2): extent item not found for insert, bytenr 179847168 num_bytes 16384 parent 4594335744 root_objectid 273 owner 0 offset 0 BTRFS error (device dm-2): failed to run delayed ref for logical 179847168 num_bytes 16384 type 182 action 1 ref_mod 1: -117 [CAUSE] The above error is showing that there is a tree reference to a metadata extent that is no longer there. With "ref_verify" mount option (requires CONFIG_BTRFS_DEBUG), there is some extra debug output: BTRFS error (device dm-2): dumping block entry [180961280 16384], num_refs 0, metadata 1, from disk 0 BTRFS error (device dm-2): root entry 256, num_refs 18446744073709551615 BTRFS error (device dm-2): root entry 273, num_refs 18446744073709551615 BTRFS error (device dm-2): Ref action 3, root 273, ref_root 273, parent 0, owner 0, offset 0, num_refs 1 btrfs_force_cow_block+0x129/0x7d0 [btrfs] btrfs_cow_block+0x10a/0x250 [btrfs] btrfs_search_slot+0x5eb/0xf40 [btrfs] btrfs_insert_empty_items+0x3a/0x70 [btrfs] insert_with_overflow+0x53/0x130 [btrfs] btrfs_insert_dir_item+0x125/0x290 [btrfs] btrfs_add_link+0xaa/0x410 [btrfs] btrfs_rename+0x5ea/0xcd0 [btrfs] btrfs_rename2+0x28/0x60 [btrfs] vfs_rename+0x5b2/0xe10 filename_renameat2+0x244/0x430 __x64_sys_rename+0x48/0x70 do_syscall_64+0xe1/0x790 entry_SYSCALL_64_after_hwframe+0x4b/0x53 ---truncated---

In the Linux kernel, the following vulnerability has been resolved: ipvs: fix reversed sequence option serialization hton_seq() expects the host-order source first and the unaligned network-order destination second. The version 1 sync sender passes these arguments in reverse for both sequence blocks. This leaves 24 bytes of the kmalloc-backed message unwritten. It may disclose stale heap data and replace the live connection sequence state with values read from the buffer. Pass the connection sequence state as the source and the message payload as the destination for both blocks.

In the Linux kernel, the following vulnerability has been resolved: ASoC: Intel: avs: Fix unbalanced module reference count strace_open() invokes try_module_get() which on success takes the module reference. If any follow up operation causes strace_open() to fail, the refcount shall be put down.

In the Linux kernel, the following vulnerability has been resolved: ASoC: Intel: avs: Refactor and fix init_config access Existing code accesses enties found in ->init_configs array through indexes that are part of ->config_ids array. Those two are limited by: ->num_init_configs and ->num_config_ids respectively. Using ID larger or equal to ->num_init_configs leads to out-of-bounds access: avs_path_module_send_init_configs() loop: (...) &acomp->tplg->init_configs[ids[i]] ^ out-of-bounds candidate Rather than adding another if-statement, refactor the code. There is no need to store the IDs, have a list of pointers to actual config-entries instead. As the verification of ->init_config entries does not differ from verification of other types that are part of the topology.c file, simply reuse the code.

In the Linux kernel, the following vulnerability has been resolved: bpf: zero extend the result of an arena 32-bit cmpxchg bpf_convert_ctx_accesses() rewrites an atomic on an arena pointer from BPF_STX | BPF_ATOMIC to BPF_STX | BPF_PROBE_ATOMIC, and it runs before bpf_opt_subreg_zext_lo32_rnd_hi32(). That pass emits an explicit zero extension for a 32-bit cmpxchg even when bpf_jit_needs_zext() is false. This is done because on some architectures 32-bit cmpxchg requires explicit zero extension for the dst register. E.g. on x86-64 'lock cmpxchg' does not change the %eax if comparison is successful, while BPF semantics declare that each operation on a 32-bit register zero extends it's upper half. is_cmpxchg_insn() matches BPF_MODE == BPF_ATOMIC only, so an arena cmpxchg misses said zero extension adjustment. This patch adjusts is_cmpxchg_insn() to match BPF_PROBE_ATOMIC alongside BPF_ATOMIC.

In the Linux kernel, the following vulnerability has been resolved: io_uring/io-wq: re-check IO_WQ_BIT_EXIT for each linked work item commit 10dc95939817 ("io_uring/io-wq: check IO_WQ_BIT_EXIT inside work run loop") fixed the obvious case where io_worker_handle_work() took one exit-bit snapshot before draining pending work, but the fix stops one level too early. io_worker_handle_work() now re-checks IO_WQ_BIT_EXIT in its outer work run loop, yet it still snapshots that bit once before processing a whole dependent linked-work chain. If io_wq_exit_start() sets IO_WQ_BIT_EXIT after the first linked item has started, the remaining linked items can still reuse stale do_kill = false, skip IO_WQ_WORK_CANCEL, and continue running after exit has begun. Move the check further inside, so it covers linked items too. Note: this is a syzbot special as it loves setting up tons of slow linked work on weird devices like msr that take forever to read, and immediately close the ring. Exit then takes a long time.