Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: can: ucan: fix out of bound read in strscpy() source Commit 7fdaf8966aae ("can: ucan: use strscpy() to instead of strncpy()") unintentionally introduced a one byte out of bound read on strscpy()'s source argument (which is kind of ironic knowing that strscpy() is meant to be a more secure alternative :)). Let's consider below buffers: dest[len + 1]; /* will be NUL terminated */ src[len]; /* may not be NUL terminated */ When doing: strncpy(dest, src, len); dest[len] = '\0'; strncpy() will read up to len bytes from src. On the other hand: strscpy(dest, src, len + 1); will read up to len + 1 bytes from src, that is to say, an out of bound read of one byte will occur on src if it is not NUL terminated. Note that the src[len] byte is never copied, but strscpy() still needs to read it to check whether a truncation occurred or not. This exact pattern happened in ucan. The root cause is that the source is not NUL terminated. Instead of doing a copy in a local buffer, directly NUL terminate it as soon as usb_control_msg() returns. With this, the local firmware_str[] variable can be removed. On top of this do a couple refactors: - ucan_ctl_payload->raw is only used for the firmware string, so rename it to ucan_ctl_payload->fw_str and change its type from u8 to char. - ucan_device_request_in() is only used to retrieve the firmware string, so rename it to ucan_get_fw_str() and refactor it to make it directly handle all the string termination logic.Show less

In the Linux kernel, the following vulnerability has been resolved: netfs: Call `invalidate_cache` only if implemented Many filesystems such as NFS and Ceph do not implement the `invalidate_cache` method. On those filesystems, if writing to the cache (`NETFS_WRITE_TO_CACHE`) fails for some reason, the kernel crashes like this: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 0 P4D 0 Oops: Oops: 0010 [#1] SMP PTI CPU: 9 UID: 0 PID: 3380 Comm: kworker/u193:11 Not tainted 6.13.3-cm4all1-hp #437 Hardware name: HP ProLiant DL380 Gen9/ProLiant DL380 Gen9, BIOS P89 10/17/2018 Workqueue: events_unbound netfs_write_collection_worker RIP: 0010:0x0 Code: Unable to access opcode bytes at 0xffffffffffffffd6. RSP: 0018:ffff9b86e2ca7dc0 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 7fffffffffffffff RDX: 0000000000000001 RSI: ffff89259d576a18 RDI: ffff89259d576900 RBP: ffff89259d5769b0 R08: ffff9b86e2ca7d28 R09: 0000000000000002 R10: ffff89258ceaca80 R11: 0000000000000001 R12: 0000000000000020 R13: ffff893d158b9338 R14: ffff89259d576900 R15: ffff89259d5769b0 FS: 0000000000000000(0000) GS:ffff893c9fa40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 000000054442e003 CR4: 00000000001706f0 Call Trace: <TASK> ? __die+0x1f/0x60 ? page_fault_oops+0x15c/0x460 ? try_to_wake_up+0x2d2/0x530 ? exc_page_fault+0x5e/0x100 ? asm_exc_page_fault+0x22/0x30 netfs_write_collection_worker+0xe9f/0x12b0 ? xs_poll_check_readable+0x3f/0x80 ? xs_stream_data_receive_workfn+0x8d/0x110 process_one_work+0x134/0x2d0 worker_thread+0x299/0x3a0 ? __pfx_worker_thread+0x10/0x10 kthread+0xba/0xe0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x30/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Modules linked in: CR2: 0000000000000000 This patch adds the missing `NULL` check.Show less

In the Linux kernel, the following vulnerability has been resolved: accel/qaic: Fix integer overflow in qaic_validate_req() These are u64 variables that come from the user via qaic_attach_slice_bo_ioctl(). Use check_add_overflow() to ensure that the math doesn't have an integer wrapping bug.Show less

In the Linux kernel, the following vulnerability has been resolved: mm/huge_memory: drop beyond-EOF folios with the right number of refs When an after-split folio is large and needs to be dropped due to EOF, folio_put_refs(folio, folio_nr_pages(folio)) should be used to drop all page cache refs. Otherwise, the folio will not be freed, causing memory leak. This leak would happen on a filesystem with blocksize > page_size and a truncate is performed, where the blocksize makes folios split to >0 order ones, causing truncated folios not being freed.Show less

In the Linux kernel, the following vulnerability has been resolved: proc: fix UAF in proc_get_inode() Fix race between rmmod and /proc/XXX's inode instantiation. The bug is that pde->proc_ops don't belong to /proc, it belongs to a module, therefore dereferencing it after /proc entry has been registered is a bug unless use_pde/unuse_pde() pair has been used. use_pde/unuse_pde can be avoided (2 atomic ops!) because pde->proc_ops never changes so information necessary for inode instantiation can be saved _before_ proc_register() in PDE itself and used later, avoiding pde->proc_ops->... dereference. rmmod lookup sys_delete_module proc_lookup_de pde_get(de); proc_get_inode(dir->i_sb, de); mod->exit() proc_remove remove_proc_subtree proc_entry_rundown(de); free_module(mod); if (S_ISREG(inode->i_mode)) if (de->proc_ops->proc_read_iter) --> As module is already freed, will trigger UAF BUG: unable to handle page fault for address: fffffbfff80a702b PGD 817fc4067 P4D 817fc4067 PUD 817fc0067 PMD 102ef4067 PTE 0 Oops: Oops: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 26 UID: 0 PID: 2667 Comm: ls Tainted: G Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) RIP: 0010:proc_get_inode+0x302/0x6e0 RSP: 0018:ffff88811c837998 EFLAGS: 00010a06 RAX: dffffc0000000000 RBX: ffffffffc0538140 RCX: 0000000000000007 RDX: 1ffffffff80a702b RSI: 0000000000000001 RDI: ffffffffc0538158 RBP: ffff8881299a6000 R08: 0000000067bbe1e5 R09: 1ffff11023906f20 R10: ffffffffb560ca07 R11: ffffffffb2b43a58 R12: ffff888105bb78f0 R13: ffff888100518048 R14: ffff8881299a6004 R15: 0000000000000001 FS: 00007f95b9686840(0000) GS:ffff8883af100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: fffffbfff80a702b CR3: 0000000117dd2000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> proc_lookup_de+0x11f/0x2e0 __lookup_slow+0x188/0x350 walk_component+0x2ab/0x4f0 path_lookupat+0x120/0x660 filename_lookup+0x1ce/0x560 vfs_statx+0xac/0x150 __do_sys_newstat+0x96/0x110 do_syscall_64+0x5f/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e [adobriyan@gmail.com: don't do 2 atomic ops on the common path]Show less

In the Linux kernel, the following vulnerability has been resolved: firmware: qcom: uefisecapp: fix efivars registration race Since the conversion to using the TZ allocator, the efivars service is registered before the memory pool has been allocated, something which can lead to a NULL-pointer dereference in case of a racing EFI variable access. Make sure that all resources have been set up before registering the efivars.Show less

In the Linux kernel, the following vulnerability has been resolved: xsk: fix an integer overflow in xp_create_and_assign_umem() Since the i and pool->chunk_size variables are of type 'u32', their product can wrap around and then be cast to 'u64'. This can lead to two different XDP buffers pointing to the same memory area. Found by InfoTeCS on behalf of Linux Verification Center (linuxtesting.org) with SVACE.Show less

In the Linux kernel, the following vulnerability has been resolved: drm/radeon: fix uninitialized size issue in radeon_vce_cs_parse() On the off chance that command stream passed from userspace via ioctl() call to radeon_vce_cs_parse() is weirdly crafted and first command to execute is to encode (case 0x03000001), the function in question will attempt to call radeon_vce_cs_reloc() with size argument that has not been properly initialized. Specifically, 'size' will point to 'tmp' variable before the latter had a chance to be assigned any value. Play it safe and init 'tmp' with 0, thus ensuring that radeon_vce_cs_reloc() will catch an early error in cases like these. Found by Linux Verification Center (linuxtesting.org) with static analysis tool SVACE. (cherry picked from commit 2d52de55f9ee7aaee0e09ac443f77855989c6b68)Show less

In the Linux kernel, the following vulnerability has been resolved: drm/sched: Fix fence reference count leak The last_scheduled fence leaks when an entity is being killed and adding the cleanup callback fails. Decrement the reference count of prev when dma_fence_add_callback() fails, ensuring proper balance. [phasta: add git tag info for stable kernel]Show less

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix incorrect validation for num_aces field of smb_acl parse_dcal() validate num_aces to allocate posix_ace_state_array. if (num_aces > ULONG_MAX / sizeof(struct smb_ace *)) It is an incorrect validation that we can create an array of size ULONG_MAX. smb_acl has ->size field to calculate actual number of aces in request buffer size. Use this to check invalid num_aces.Show less

In the Linux kernel, the following vulnerability has been resolved: iscsi_ibft: Fix UBSAN shift-out-of-bounds warning in ibft_attr_show_nic() When performing an iSCSI boot using IPv6, iscsistart still reads the /sys/firmware/ibft/ethernetX/subnet-mask entry. Since the IPv6 prefix length is 64, this causes the shift exponent to become negative, triggering a UBSAN warning. As the concept of a subnet mask does not apply to IPv6, the value is set to ~0 to suppress the warning message.Show less

In the Linux kernel, the following vulnerability has been resolved: HID: ignore non-functional sensor in HP 5MP Camera The HP 5MP Camera (USB ID 0408:5473) reports a HID sensor interface that is not actually implemented. Attempting to access this non-functional sensor via iio_info causes system hangs as runtime PM tries to wake up an unresponsive sensor. [453] hid-sensor-hub 0003:0408:5473.0003: Report latency attributes: ffffffff:ffffffff [453] hid-sensor-hub 0003:0408:5473.0003: common attributes: 5:1, 2:1, 3:1 ffffffff:ffffffff Add this device to the HID ignore list since the sensor interface is non-functional by design and should not be exposed to userspace.Show less

In the Linux kernel, the following vulnerability has been resolved: x86/microcode/AMD: Fix out-of-bounds on systems with CPU-less NUMA nodes Currently, load_microcode_amd() iterates over all NUMA nodes, retrieves their CPU masks and unconditionally accesses per-CPU data for the first CPU of each mask. According to Documentation/admin-guide/mm/numaperf.rst: "Some memory may share the same node as a CPU, and others are provided as memory only nodes." Therefore, some node CPU masks may be empty and wouldn't have a "first CPU". On a machine with far memory (and therefore CPU-less NUMA nodes): - cpumask_of_node(nid) is 0 - cpumask_first(0) is CONFIG_NR_CPUS - cpu_data(CONFIG_NR_CPUS) accesses the cpu_info per-CPU array at an index that is 1 out of bounds This does not have any security implications since flashing microcode is a privileged operation but I believe this has reliability implications by potentially corrupting memory while flashing a microcode update. When booting with CONFIG_UBSAN_BOUNDS=y on an AMD machine that flashes a microcode update. I get the following splat: UBSAN: array-index-out-of-bounds in arch/x86/kernel/cpu/microcode/amd.c:X:Y index 512 is out of range for type 'unsigned long[512]' [...] Call Trace: dump_stack __ubsan_handle_out_of_bounds load_microcode_amd request_microcode_amd reload_store kernfs_fop_write_iter vfs_write ksys_write do_syscall_64 entry_SYSCALL_64_after_hwframe Change the loop to go over only NUMA nodes which have CPUs before determining whether the first CPU on the respective node needs microcode update. [ bp: Massage commit message, fix typo. ]Show less

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: NULL-check BO's backing store when determining GFX12 PTE flags PRT BOs may not have any backing store, so bo->tbo.resource will be NULL. Check for that before dereferencing. (cherry picked from commit 3e3fcd29b505cebed659311337ea03b7698767fc)Show less

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: fix missing .is_two_pixels_per_container Starting from 6.11, AMDGPU driver, while being loaded with amdgpu.dc=1, due to lack of .is_two_pixels_per_container function in dce60_tg_funcs, causes a NULL pointer dereference on PCs with old GPUs, such as R9 280X. So this fix adds missing .is_two_pixels_per_container to dce60_tg_funcs. (cherry picked from commit bd4b125eb949785c6f8a53b0494e32795421209d)Show less

In the Linux kernel, the following vulnerability has been resolved: fs/netfs/read_collect: add to next->prev_donated If multiple subrequests donate data to the same "next" request (depending on the subrequest completion order), each of them would overwrite the `prev_donated` field, causing data corruption and a BUG() crash ("Can't donate prior to front").Show less

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: init return value in amdgpu_ttm_clear_buffer Otherwise an uninitialized value can be returned if amdgpu_res_cleared returns true for all regions. Possibly closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3812 (cherry picked from commit 7c62aacc3b452f73a1284198c81551035fac6d71)Show less

In the Linux kernel, the following vulnerability has been resolved: net: switchdev: Convert blocking notification chain to a raw one A blocking notification chain uses a read-write semaphore to protect the integrity of the chain. The semaphore is acquired for writing when adding / removing notifiers to / from the chain and acquired for reading when traversing the chain and informing notifiers about an event. In case of the blocking switchdev notification chain, recursive notifications are possible which leads to the semaphore being acquired twice for reading and to lockdep warnings being generated [1]. Specifically, this can happen when the bridge driver processes a SWITCHDEV_BRPORT_UNOFFLOADED event which causes it to emit notifications about deferred events when calling switchdev_deferred_process(). Fix this by converting the notification chain to a raw notification chain in a similar fashion to the netdev notification chain. Protect the chain using the RTNL mutex by acquiring it when modifying the chain. Events are always informed under the RTNL mutex, but add an assertion in call_switchdev_blocking_notifiers() to make sure this is not violated in the future. Maintain the "blocking" prefix as events are always emitted from process context and listeners are allowed to block. [1]: WARNING: possible recursive locking detected 6.14.0-rc4-custom-g079270089484 #1 Not tainted -------------------------------------------- ip/52731 is trying to acquire lock: ffffffff850918d8 ((switchdev_blocking_notif_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x58/0xa0 but task is already holding lock: ffffffff850918d8 ((switchdev_blocking_notif_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x58/0xa0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock((switchdev_blocking_notif_chain).rwsem); lock((switchdev_blocking_notif_chain).rwsem); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by ip/52731: #0: ffffffff84f795b0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x727/0x1dc0 #1: ffffffff8731f628 (&net->rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x790/0x1dc0 #2: ffffffff850918d8 ((switchdev_blocking_notif_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x58/0xa0 stack backtrace: ... ? __pfx_down_read+0x10/0x10 ? __pfx_mark_lock+0x10/0x10 ? __pfx_switchdev_port_attr_set_deferred+0x10/0x10 blocking_notifier_call_chain+0x58/0xa0 switchdev_port_attr_notify.constprop.0+0xb3/0x1b0 ? __pfx_switchdev_port_attr_notify.constprop.0+0x10/0x10 ? mark_held_locks+0x94/0xe0 ? switchdev_deferred_process+0x11a/0x340 switchdev_port_attr_set_deferred+0x27/0xd0 switchdev_deferred_process+0x164/0x340 br_switchdev_port_unoffload+0xc8/0x100 [bridge] br_switchdev_blocking_event+0x29f/0x580 [bridge] notifier_call_chain+0xa2/0x440 blocking_notifier_call_chain+0x6e/0xa0 switchdev_bridge_port_unoffload+0xde/0x1a0 ...Show less

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix out-of-bound accesses [WHAT & HOW] hpo_stream_to_link_encoder_mapping has size MAX_HPO_DP2_ENCODERS(=4), but location can have size up to 6. As a result, it is necessary to check location against MAX_HPO_DP2_ENCODERS. Similiarly, disp_cfg_stream_location can be used as an array index which should be 0..5, so the ASSERT's conditions should be less without equal.Show less

In the Linux kernel, the following vulnerability has been resolved: mm: fix kernel BUG when userfaultfd_move encounters swapcache userfaultfd_move() checks whether the PTE entry is present or a swap entry. - If the PTE entry is present, move_present_pte() handles folio migration by setting: src_folio->index = linear_page_index(dst_vma, dst_addr); - If the PTE entry is a swap entry, move_swap_pte() simply copies the PTE to the new dst_addr. This approach is incorrect because, even if the PTE is a swap entry, it can still reference a folio that remains in the swap cache. This creates a race window between steps 2 and 4. 1. add_to_swap: The folio is added to the swapcache. 2. try_to_unmap: PTEs are converted to swap entries. 3. pageout: The folio is written back. 4. Swapcache is cleared. If userfaultfd_move() occurs in the window between steps 2 and 4, after the swap PTE has been moved to the destination, accessing the destination triggers do_swap_page(), which may locate the folio in the swapcache. However, since the folio's index has not been updated to match the destination VMA, do_swap_page() will detect a mismatch. This can result in two critical issues depending on the system configuration. If KSM is disabled, both small and large folios can trigger a BUG during the add_rmap operation due to: page_pgoff(folio, page) != linear_page_index(vma, address) [ 13.336953] page: refcount:6 mapcount:1 mapping:00000000f43db19c index:0xffffaf150 pfn:0x4667c [ 13.337520] head: order:2 mapcount:1 entire_mapcount:0 nr_pages_mapped:1 pincount:0 [ 13.337716] memcg:ffff00000405f000 [ 13.337849] anon flags: 0x3fffc0000020459(locked|uptodate|dirty|owner_priv_1|head|swapbacked|node=0|zone=0|lastcpupid=0xffff) [ 13.338630] raw: 03fffc0000020459 ffff80008507b538 ffff80008507b538 ffff000006260361 [ 13.338831] raw: 0000000ffffaf150 0000000000004000 0000000600000000 ffff00000405f000 [ 13.339031] head: 03fffc0000020459 ffff80008507b538 ffff80008507b538 ffff000006260361 [ 13.339204] head: 0000000ffffaf150 0000000000004000 0000000600000000 ffff00000405f000 [ 13.339375] head: 03fffc0000000202 fffffdffc0199f01 ffffffff00000000 0000000000000001 [ 13.339546] head: 0000000000000004 0000000000000000 00000000ffffffff 0000000000000000 [ 13.339736] page dumped because: VM_BUG_ON_PAGE(page_pgoff(folio, page) != linear_page_index(vma, address)) [ 13.340190] ------------[ cut here ]------------ [ 13.340316] kernel BUG at mm/rmap.c:1380! [ 13.340683] Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP [ 13.340969] Modules linked in: [ 13.341257] CPU: 1 UID: 0 PID: 107 Comm: a.out Not tainted 6.14.0-rc3-gcf42737e247a-dirty #299 [ 13.341470] Hardware name: linux,dummy-virt (DT) [ 13.341671] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 13.341815] pc : __page_check_anon_rmap+0xa0/0xb0 [ 13.341920] lr : __page_check_anon_rmap+0xa0/0xb0 [ 13.342018] sp : ffff80008752bb20 [ 13.342093] x29: ffff80008752bb20 x28: fffffdffc0199f00 x27: 0000000000000001 [ 13.342404] x26: 0000000000000000 x25: 0000000000000001 x24: 0000000000000001 [ 13.342575] x23: 0000ffffaf0d0000 x22: 0000ffffaf0d0000 x21: fffffdffc0199f00 [ 13.342731] x20: fffffdffc0199f00 x19: ffff000006210700 x18: 00000000ffffffff [ 13.342881] x17: 6c203d2120296567 x16: 6170202c6f696c6f x15: 662866666f67705f [ 13.343033] x14: 6567617028454741 x13: 2929737365726464 x12: ffff800083728ab0 [ 13.343183] x11: ffff800082996bf8 x10: 0000000000000fd7 x9 : ffff80008011bc40 [ 13.343351] x8 : 0000000000017fe8 x7 : 00000000fffff000 x6 : ffff8000829eebf8 [ 13.343498] x5 : c0000000fffff000 x4 : 0000000000000000 x3 : 0000000000000000 [ 13.343645] x2 : 0000000000000000 x1 : ffff0000062db980 x0 : 000000000000005f [ 13.343876] Call trace: [ 13.344045] __page_check_anon_rmap+0xa0/0xb0 (P) [ 13.344234] folio_add_anon_rmap_ptes+0x22c/0x320 [ 13.344333] do_swap_page+0x1060/0x1400 [ 13.344417] __handl ---truncated---Show less