In the Linux kernel, the following vulnerability has been resolved: padata: Fix possible divide-by-0 panic in padata_mt_helper() We are hit with a not easily reproducible divide-by-0 panic in padata.c at bootup time. [ 10.017908] Oops: divide error: 0000 1 PREEMPT SMP NOPTI [ 10.017908] CPU: 26 PID: 2627 Comm: kworker/u1666:1 Not tainted 6.10.0-15.el10.x86_64 #1 [ 10.017908] Hardware name: Lenovo ThinkSystem SR950 [7X12CTO1WW]/[7X12CTO1WW], BIOS [PSE140J-2.30] 07/20/2021 [ 10.017908] Workqueue: events_unbound padata_mt_helper [ 10.017908] RIP: 0010:padata_mt_helper+0x39/0xb0 : [ 10.017963] Call Trace: [ 10.017968] <TASK> [ 10.018004] ? padata_mt_helper+0x39/0xb0 [ 10.018084] process_one_work+0x174/0x330 [ 10.018093] worker_thread+0x266/0x3a0 [ 10.018111] kthread+0xcf/0x100 [ 10.018124] ret_from_fork+0x31/0x50 [ 10.018138] ret_from_fork_asm+0x1a/0x30 [ 10.018147] </TASK> Looking at the padata_mt_helper() function, the only way a divide-by-0 panic can happen is when ps->chunk_size is 0. The way that chunk_size is initialized in padata_do_multithreaded(), chunk_size can be 0 when the min_chunk in the passed-in padata_mt_job structure is 0. Fix this divide-by-0 panic by making sure that chunk_size will be at least 1 no matter what the input parameters are.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Add null check in resource_log_pipe_topology_update [WHY] When switching from "Extend" to "Second Display Only" we sometimes call resource_get_otg_master_for_stream on a stream for the eDP, which is disconnected. This leads to a null pointer dereference. [HOW] Added a null check in dc_resource.c/resource_log_pipe_topology_update.

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: MGMT: Add error handling to pair_device() hci_conn_params_add() never checks for a NULL value and could lead to a NULL pointer dereference causing a crash. Fixed by adding error handling in the function.

In the Linux kernel, the following vulnerability has been resolved: misc: fastrpc: Fix use-after-free race condition for maps It is possible that in between calling fastrpc_map_get() until map->fl->lock is taken in fastrpc_free_map(), another thread can call fastrpc_map_lookup() and get a reference to a map that is about to be deleted. Rewrite fastrpc_map_get() to only increase the reference count of a map if it's non-zero. Propagate this to callers so they can know if a map is about to be deleted. Fixes this warning: refcount_t: addition on 0; use-after-free. WARNING: CPU: 5 PID: 10100 at lib/refcount.c:25 refcount_warn_saturate ... Call trace: refcount_warn_saturate [fastrpc_map_get inlined] [fastrpc_map_lookup inlined] fastrpc_map_create fastrpc_internal_invoke fastrpc_device_ioctl __arm64_sys_ioctl invoke_syscall

In the Linux kernel, the following vulnerability has been resolved: exec: Fix ToCToU between perm check and set-uid/gid usage When opening a file for exec via do_filp_open(), permission checking is done against the file's metadata at that moment, and on success, a file pointer is passed back. Much later in the execve() code path, the file metadata (specifically mode, uid, and gid) is used to determine if/how to set the uid and gid. However, those values may have changed since the permissions check, meaning the execution may gain unintended privileges. For example, if a file could change permissions from executable and not set-id: ---------x 1 root root 16048 Aug 7 13:16 target to set-id and non-executable: ---S------ 1 root root 16048 Aug 7 13:16 target it is possible to gain root privileges when execution should have been disallowed. While this race condition is rare in real-world scenarios, it has been observed (and proven exploitable) when package managers are updating the setuid bits of installed programs. Such files start with being world-executable but then are adjusted to be group-exec with a set-uid bit. For example, "chmod o-x,u+s target" makes "target" executable only by uid "root" and gid "cdrom", while also becoming setuid-root: -rwxr-xr-x 1 root cdrom 16048 Aug 7 13:16 target becomes: -rwsr-xr-- 1 root cdrom 16048 Aug 7 13:16 target But racing the chmod means users without group "cdrom" membership can get the permission to execute "target" just before the chmod, and when the chmod finishes, the exec reaches brpm_fill_uid(), and performs the setuid to root, violating the expressed authorization of "only cdrom group members can setuid to root". Re-check that we still have execute permissions in case the metadata has changed. It would be better to keep a copy from the perm-check time, but until we can do that refactoring, the least-bad option is to do a full inode_permission() call (under inode lock). It is understood that this is safe against dead-locks, but hardly optimal.

In the Linux kernel, the following vulnerability has been resolved: vhost/vsock: always initialize seqpacket_allow There are two issues around seqpacket_allow: 1. seqpacket_allow is not initialized when socket is created. Thus if features are never set, it will be read uninitialized. 2. if VIRTIO_VSOCK_F_SEQPACKET is set and then cleared, then seqpacket_allow will not be cleared appropriately (existing apps I know about don't usually do this but it's legal and there's no way to be sure no one relies on this). To fix: - initialize seqpacket_allow after allocation - set it unconditionally in set_features

In the Linux kernel, the following vulnerability has been resolved: RDMA/hns: Fix soft lockup under heavy CEQE load CEQEs are handled in interrupt handler currently. This may cause the CPU core staying in interrupt context too long and lead to soft lockup under heavy load. Handle CEQEs in BH workqueue and set an upper limit for the number of CEQE handled by a single call of work handler.

In the Linux kernel, the following vulnerability has been resolved: devres: Fix memory leakage caused by driver API devm_free_percpu() It will cause memory leakage when use driver API devm_free_percpu() to free memory allocated by devm_alloc_percpu(), fixed by using devres_release() instead of devres_destroy() within devm_free_percpu().

In the Linux kernel, the following vulnerability has been resolved: drm/vmwgfx: Fix a deadlock in dma buf fence polling Introduce a version of the fence ops that on release doesn't remove the fence from the pending list, and thus doesn't require a lock to fix poll->fence wait->fence unref deadlocks. vmwgfx overwrites the wait callback to iterate over the list of all fences and update their status, to do that it holds a lock to prevent the list modifcations from other threads. The fence destroy callback both deletes the fence and removes it from the list of pending fences, for which it holds a lock. dma buf polling cb unrefs a fence after it's been signaled: so the poll calls the wait, which signals the fences, which are being destroyed. The destruction tries to acquire the lock on the pending fences list which it can never get because it's held by the wait from which it was called. Old bug, but not a lot of userspace apps were using dma-buf polling interfaces. Fix those, in particular this fixes KDE stalls/deadlock.

In the Linux kernel, the following vulnerability has been resolved: net: usb: qmi_wwan: fix memory leak for not ip packets Free the unused skb when not ip packets arrive.

In the Linux kernel, the following vulnerability has been resolved: remoteproc: imx_rproc: Skip over memory region when node value is NULL In imx_rproc_addr_init() "nph = of_count_phandle_with_args()" just counts number of phandles. But phandles may be empty. So of_parse_phandle() in the parsing loop (0 < a < nph) may return NULL which is later dereferenced. Adjust this issue by adding NULL-return check. Found by Linux Verification Center (linuxtesting.org) with SVACE. [Fixed title to fit within the prescribed 70-75 charcters]

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to truncate preallocated blocks in f2fs_file_open() chenyuwen reports a f2fs bug as below: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000011 fscrypt_set_bio_crypt_ctx+0x78/0x1e8 f2fs_grab_read_bio+0x78/0x208 f2fs_submit_page_read+0x44/0x154 f2fs_get_read_data_page+0x288/0x5f4 f2fs_get_lock_data_page+0x60/0x190 truncate_partial_data_page+0x108/0x4fc f2fs_do_truncate_blocks+0x344/0x5f0 f2fs_truncate_blocks+0x6c/0x134 f2fs_truncate+0xd8/0x200 f2fs_iget+0x20c/0x5ac do_garbage_collect+0x5d0/0xf6c f2fs_gc+0x22c/0x6a4 f2fs_disable_checkpoint+0xc8/0x310 f2fs_fill_super+0x14bc/0x1764 mount_bdev+0x1b4/0x21c f2fs_mount+0x20/0x30 legacy_get_tree+0x50/0xbc vfs_get_tree+0x5c/0x1b0 do_new_mount+0x298/0x4cc path_mount+0x33c/0x5fc __arm64_sys_mount+0xcc/0x15c invoke_syscall+0x60/0x150 el0_svc_common+0xb8/0xf8 do_el0_svc+0x28/0xa0 el0_svc+0x24/0x84 el0t_64_sync_handler+0x88/0xec It is because inode.i_crypt_info is not initialized during below path: - mount - f2fs_fill_super - f2fs_disable_checkpoint - f2fs_gc - f2fs_iget - f2fs_truncate So, let's relocate truncation of preallocated blocks to f2fs_file_open(), after fscrypt_file_open().

In the Linux kernel, the following vulnerability has been resolved: jfs: Fix array-index-out-of-bounds in diFree

In the Linux kernel, the following vulnerability has been resolved: dma: fix call order in dmam_free_coherent dmam_free_coherent() frees a DMA allocation, which makes the freed vaddr available for reuse, then calls devres_destroy() to remove and free the data structure used to track the DMA allocation. Between the two calls, it is possible for a concurrent task to make an allocation with the same vaddr and add it to the devres list. If this happens, there will be two entries in the devres list with the same vaddr and devres_destroy() can free the wrong entry, triggering the WARN_ON() in dmam_match. Fix by destroying the devres entry before freeing the DMA allocation. kokonut //net/encryption http://sponge2/b9145fe6-0f72-4325-ac2f-a84d81075b03

In the Linux kernel, the following vulnerability has been resolved: md: fix deadlock between mddev_suspend and flush bio Deadlock occurs when mddev is being suspended while some flush bio is in progress. It is a complex issue. T1. the first flush is at the ending stage, it clears 'mddev->flush_bio' and tries to submit data, but is blocked because mddev is suspended by T4. T2. the second flush sets 'mddev->flush_bio', and attempts to queue md_submit_flush_data(), which is already running (T1) and won't execute again if on the same CPU as T1. T3. the third flush inc active_io and tries to flush, but is blocked because 'mddev->flush_bio' is not NULL (set by T2). T4. mddev_suspend() is called and waits for active_io dec to 0 which is inc by T3. T1 T2 T3 T4 (flush 1) (flush 2) (third 3) (suspend) md_submit_flush_data mddev->flush_bio = NULL; . . md_flush_request . mddev->flush_bio = bio . queue submit_flushes . . . . md_handle_request . . active_io + 1 . . md_flush_request . . wait !mddev->flush_bio . . . . mddev_suspend . . wait !active_io . . . submit_flushes . queue_work md_submit_flush_data . //md_submit_flush_data is already running (T1) . md_handle_request wait resume The root issue is non-atomic inc/dec of active_io during flush process. active_io is dec before md_submit_flush_data is queued, and inc soon after md_submit_flush_data() run. md_flush_request active_io + 1 submit_flushes active_io - 1 md_submit_flush_data md_handle_request active_io + 1 make_request active_io - 1 If active_io is dec after md_handle_request() instead of within submit_flushes(), make_request() can be called directly intead of md_handle_request() in md_submit_flush_data(), and active_io will only inc and dec once in the whole flush process. Deadlock will be fixed. Additionally, the only difference between fixing the issue and before is that there is no return error handling of make_request(). But after previous patch cleaned md_write_start(), make_requst() only return error in raid5_make_request() by dm-raid, see commit 41425f96d7aa ("dm-raid456, md/raid456: fix a deadlock for dm-raid456 while io concurrent with reshape)". Since dm always splits data and flush operation into two separate io, io size of flush submitted by dm always is 0, make_request() will not be called in md_submit_flush_data(). To prevent future modifications from introducing issues, add WARN_ON to ensure make_request() no error is returned in this context.

In the Linux kernel, the following vulnerability has been resolved: block: initialize integrity buffer to zero before writing it to media Metadata added by bio_integrity_prep is using plain kmalloc, which leads to random kernel memory being written media. For PI metadata this is limited to the app tag that isn't used by kernel generated metadata, but for non-PI metadata the entire buffer leaks kernel memory. Fix this by adding the __GFP_ZERO flag to allocations for writes.

In the Linux kernel, the following vulnerability has been resolved: cgroup/cpuset: Prevent UAF in proc_cpuset_show() An UAF can happen when /proc/cpuset is read as reported in [1]. This can be reproduced by the following methods: 1.add an mdelay(1000) before acquiring the cgroup_lock In the cgroup_path_ns function. 2.$cat /proc/<pid>/cpuset repeatly. 3.$mount -t cgroup -o cpuset cpuset /sys/fs/cgroup/cpuset/ $umount /sys/fs/cgroup/cpuset/ repeatly. The race that cause this bug can be shown as below: (umount) | (cat /proc/<pid>/cpuset) css_release | proc_cpuset_show css_release_work_fn | css = task_get_css(tsk, cpuset_cgrp_id); css_free_rwork_fn | cgroup_path_ns(css->cgroup, ...); cgroup_destroy_root | mutex_lock(&cgroup_mutex); rebind_subsystems | cgroup_free_root | | // cgrp was freed, UAF | cgroup_path_ns_locked(cgrp,..); When the cpuset is initialized, the root node top_cpuset.css.cgrp will point to &cgrp_dfl_root.cgrp. In cgroup v1, the mount operation will allocate cgroup_root, and top_cpuset.css.cgrp will point to the allocated &cgroup_root.cgrp. When the umount operation is executed, top_cpuset.css.cgrp will be rebound to &cgrp_dfl_root.cgrp. The problem is that when rebinding to cgrp_dfl_root, there are cases where the cgroup_root allocated by setting up the root for cgroup v1 is cached. This could lead to a Use-After-Free (UAF) if it is subsequently freed. The descendant cgroups of cgroup v1 can only be freed after the css is released. However, the css of the root will never be released, yet the cgroup_root should be freed when it is unmounted. This means that obtaining a reference to the css of the root does not guarantee that css.cgrp->root will not be freed. Fix this problem by using rcu_read_lock in proc_cpuset_show(). As cgroup_root is kfree_rcu after commit d23b5c577715 ("cgroup: Make operations on the cgroup root_list RCU safe"), css->cgroup won't be freed during the critical section. To call cgroup_path_ns_locked, css_set_lock is needed, so it is safe to replace task_get_css with task_css. [1] https://syzkaller.appspot.com/bug?extid=9b1ff7be974a403aa4cd

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix null pointer dereference in resolve_prog_type() for BPF_PROG_TYPE_EXT When loading a EXT program without specifying `attr->attach_prog_fd`, the `prog->aux->dst_prog` will be null. At this time, calling resolve_prog_type() anywhere will result in a null pointer dereference. Example stack trace: [ 8.107863] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000004 [ 8.108262] Mem abort info: [ 8.108384] ESR = 0x0000000096000004 [ 8.108547] EC = 0x25: DABT (current EL), IL = 32 bits [ 8.108722] SET = 0, FnV = 0 [ 8.108827] EA = 0, S1PTW = 0 [ 8.108939] FSC = 0x04: level 0 translation fault [ 8.109102] Data abort info: [ 8.109203] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 [ 8.109399] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 8.109614] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 8.109836] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000101354000 [ 8.110011] [0000000000000004] pgd=0000000000000000, p4d=0000000000000000 [ 8.112624] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP [ 8.112783] Modules linked in: [ 8.113120] CPU: 0 PID: 99 Comm: may_access_dire Not tainted 6.10.0-rc3-next-20240613-dirty #1 [ 8.113230] Hardware name: linux,dummy-virt (DT) [ 8.113390] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 8.113429] pc : may_access_direct_pkt_data+0x24/0xa0 [ 8.113746] lr : add_subprog_and_kfunc+0x634/0x8e8 [ 8.113798] sp : ffff80008283b9f0 [ 8.113813] x29: ffff80008283b9f0 x28: ffff800082795048 x27: 0000000000000001 [ 8.113881] x26: ffff0000c0bb2600 x25: 0000000000000000 x24: 0000000000000000 [ 8.113897] x23: ffff0000c1134000 x22: 000000000001864f x21: ffff0000c1138000 [ 8.113912] x20: 0000000000000001 x19: ffff0000c12b8000 x18: ffffffffffffffff [ 8.113929] x17: 0000000000000000 x16: 0000000000000000 x15: 0720072007200720 [ 8.113944] x14: 0720072007200720 x13: 0720072007200720 x12: 0720072007200720 [ 8.113958] x11: 0720072007200720 x10: 0000000000f9fca4 x9 : ffff80008021f4e4 [ 8.113991] x8 : 0101010101010101 x7 : 746f72705f6d656d x6 : 000000001e0e0f5f [ 8.114006] x5 : 000000000001864f x4 : ffff0000c12b8000 x3 : 000000000000001c [ 8.114020] x2 : 0000000000000002 x1 : 0000000000000000 x0 : 0000000000000000 [ 8.114126] Call trace: [ 8.114159] may_access_direct_pkt_data+0x24/0xa0 [ 8.114202] bpf_check+0x3bc/0x28c0 [ 8.114214] bpf_prog_load+0x658/0xa58 [ 8.114227] __sys_bpf+0xc50/0x2250 [ 8.114240] __arm64_sys_bpf+0x28/0x40 [ 8.114254] invoke_syscall.constprop.0+0x54/0xf0 [ 8.114273] do_el0_svc+0x4c/0xd8 [ 8.114289] el0_svc+0x3c/0x140 [ 8.114305] el0t_64_sync_handler+0x134/0x150 [ 8.114331] el0t_64_sync+0x168/0x170 [ 8.114477] Code: 7100707f 54000081 f9401c00 f9403800 (b9400403) [ 8.118672] ---[ end trace 0000000000000000 ]--- One way to fix it is by forcing `attach_prog_fd` non-empty when bpf_prog_load(). But this will lead to `libbpf_probe_bpf_prog_type` API broken which use verifier log to probe prog type and will log nothing if we reject invalid EXT prog before bpf_check(). Another way is by adding null check in resolve_prog_type(). The issue was introduced by commit 4a9c7bbe2ed4 ("bpf: Resolve to prog->aux->dst_prog->type only for BPF_PROG_TYPE_EXT") which wanted to correct type resolution for BPF_PROG_TYPE_TRACING programs. Before that, the type resolution of BPF_PROG_TYPE_EXT prog actually follows the logic below: prog->aux->dst_prog ? prog->aux->dst_prog->type : prog->type; It implies that when EXT program is not yet attached to `dst_prog`, the prog type should be EXT itself. This code worked fine in the past. So just keep using it. Fix this by returning `prog->type` for BPF_PROG_TYPE_EXT if `dst_prog` is not present in resolve_prog_type().

In the Linux kernel, the following vulnerability has been resolved: media: v4l: async: Fix NULL pointer dereference in adding ancillary links In v4l2_async_create_ancillary_links(), ancillary links are created for lens and flash sub-devices. These are sub-device to sub-device links and if the async notifier is related to a V4L2 device, the source sub-device of the ancillary link is NULL, leading to a NULL pointer dereference. Check the notifier's sd field is non-NULL in v4l2_async_create_ancillary_links(). [Sakari Ailus: Reword the subject and commit messages slightly.]

In the Linux kernel, the following vulnerability has been resolved: ext4: fix infinite loop when replaying fast_commit When doing fast_commit replay an infinite loop may occur due to an uninitialized extent_status struct. ext4_ext_determine_insert_hole() does not detect the replay and calls ext4_es_find_extent_range(), which will return immediately without initializing the 'es' variable. Because 'es' contains garbage, an integer overflow may happen causing an infinite loop in this function, easily reproducible using fstest generic/039. This commit fixes this issue by unconditionally initializing the structure in function ext4_es_find_extent_range(). Thanks to Zhang Yi, for figuring out the real problem!