The Linux Kernel, the operating system core itself.

Security Fix(es):

In the Linux kernel, the following vulnerability has been resolved:

btrfs: get rid of warning on transaction commit when using flushoncommit

When using the flushoncommit mount option, during almost every transaction commit we trigger a warning from __writeback_inodes_sb_nr():

$ cat fs/fs-writeback.c: (...) static void __writeback_inodes_sb_nr(struct super_block *sb, ... { (...) WARN_ON(!rwsem_is_locked(&sb->s_umount)); (...) } (...)

The trace produced in dmesg looks like the following:

[947.473890] WARNING: CPU: 5 PID: 930 at fs/fs-writeback.c:2610 __writeback_inodes_sb_nr+0x7e/0xb3 [947.481623] Modules linked in: nfsd nls_cp437 cifs asn1_decoder cifs_arc4 fscache cifs_md4 ipmi_ssif [947.489571] CPU: 5 PID: 930 Comm: btrfs-transacti Not tainted 95.16.3-srb-asrock-00001-g36437ad63879 #186 [947.497969] RIP: 0010:__writeback_inodes_sb_nr+0x7e/0xb3 [947.502097] Code: 24 10 4c 89 44 24 18 c6 (...) [947.519760] RSP: 0018:ffffc90000777e10 EFLAGS: 00010246 [947.523818] RAX: 0000000000000000 RBX: 0000000000963300 RCX: 0000000000000000 [947.529765] RDX: 0000000000000000 RSI: 000000000000fa51 RDI: ffffc90000777e50 [947.535740] RBP: ffff888101628a90 R08: ffff888100955800 R09: ffff888100956000 [947.541701] R10: 0000000000000002 R11: 0000000000000001 R12: ffff888100963488 [947.547645] R13: ffff888100963000 R14: ffff888112fb7200 R15: ffff888100963460 [947.553621] FS: 0000000000000000(0000) GS:ffff88841fd40000(0000) knlGS:0000000000000000 [947.560537] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [947.565122] CR2: 0000000008be50c4 CR3: 000000000220c000 CR4: 00000000001006e0 [947.571072] Call Trace: [947.572354] <TASK> [947.573266] btrfs_commit_transaction+0x1f1/0x998 [947.576785] ? start_transaction+0x3ab/0x44e [947.579867] ? schedule_timeout+0x8a/0xdd [947.582716] transaction_kthread+0xe9/0x156 [947.585721] ? btrfs_cleanup_transaction.isra.0+0x407/0x407 [947.590104] kthread+0x131/0x139 [947.592168] ? set_kthread_struct+0x32/0x32 [947.595174] ret_from_fork+0x22/0x30 [947.597561] </TASK> [947.598553] ---[ end trace 644721052755541c ]---

This is because we started using writeback_inodes_sb() to flush delalloc when committing a transaction (when using -o flushoncommit), in order to avoid deadlocks with filesystem freeze operations. This change was made by commit ce8ea7cc6eb313 ("btrfs: don't call btrfs_start_delalloc_roots in flushoncommit"). After that change we started producing that warning, and every now and then a user reports this since the warning happens too often, it spams dmesg/syslog, and a user is unsure if this reflects any problem that might compromise the filesystem's reliability.

We can not just lock the sb->s_umount semaphore before calling writeback_inodes_sb(), because that would at least deadlock with filesystem freezing, since at fs/super.c:freeze_super() sync_filesystem() is called while we are holding that semaphore in write mode, and that can trigger a transaction commit, resulting in a deadlock. It would also trigger the same type of deadlock in the unmount path. Possibly, it could also introduce some other locking dependencies that lockdep would report.

To fix this call try_to_writeback_inodes_sb() instead of writeback_inodes_sb(), because that will try to read lock sb->s_umount and then will only call writeback_inodes_sb() if it was able to lock it. This is fine because the cases where it can't read lock sb->s_umount are during a filesystem unmount or during a filesystem freeze - in those cases sb->s_umount is write locked and sync_filesystem() is called, which calls writeback_inodes_sb(). In other words, in all cases where we can't take a read lock on sb->s_umount, writeback is already being triggered elsewhere.

An alternative would be to call btrfs_start_delalloc_roots() with a number of pages different from LONG_MAX, for example matching the number of delalloc bytes we currently have, in ---truncated---(CVE-2022-48920)

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_tables: unregister flowtable hooks on netns exit

Unregister flowtable hooks before they are releases via nf_tables_flowtable_destroy() otherwise hook core reports UAF.

BUG: KASAN: use-after-free in nf_hook_entries_grow+0x5a7/0x700 net/netfilter/core.c:142 net/netfilter/core.c:142 Read of size 4 at addr ffff8880736f7438 by task syz-executor579/3666

CPU: 0 PID: 3666 Comm: syz-executor579 Not tainted 5.16.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] __dump_stack lib/dump_stack.c:88 [inline] lib/dump_stack.c:106 dump_stack_lvl+0x1dc/0x2d8 lib/dump_stack.c:106 lib/dump_stack.c:106 print_address_description+0x65/0x380 mm/kasan/report.c:247 mm/kasan/report.c:247 __kasan_report mm/kasan/report.c:433 [inline] __kasan_report mm/kasan/report.c:433 [inline] mm/kasan/report.c:450 kasan_report+0x19a/0x1f0 mm/kasan/report.c:450 mm/kasan/report.c:450 nf_hook_entries_grow+0x5a7/0x700 net/netfilter/core.c:142 net/netfilter/core.c:142 __nf_register_net_hook+0x27e/0x8d0 net/netfilter/core.c:429 net/netfilter/core.c:429 nf_register_net_hook+0xaa/0x180 net/netfilter/core.c:571 net/netfilter/core.c:571 nft_register_flowtable_net_hooks+0x3c5/0x730 net/netfilter/nf_tables_api.c:7232 net/netfilter/nf_tables_api.c:7232 nf_tables_newflowtable+0x2022/0x2cf0 net/netfilter/nf_tables_api.c:7430 net/netfilter/nf_tables_api.c:7430 nfnetlink_rcv_batch net/netfilter/nfnetlink.c:513 [inline] nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline] nfnetlink_rcv_batch net/netfilter/nfnetlink.c:513 [inline] net/netfilter/nfnetlink.c:652 nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline] net/netfilter/nfnetlink.c:652 nfnetlink_rcv+0x10e6/0x2550 net/netfilter/nfnetlink.c:652 net/netfilter/nfnetlink.c:652

__nft_release_hook() calls nft_unregister_flowtable_net_hooks() which only unregisters the hooks, then after RCU grace period, it is guaranteed that no packets add new entries to the flowtable (no flow offload rules and flowtable hooks are reachable from packet path), so it is safe to call nf_flow_table_free() which cleans up the remaining entries from the flowtable (both software and hardware) and it unbinds the flow_block.(CVE-2022-48935)

In the Linux kernel, the following vulnerability has been resolved:

phonet: fix rtm_phonet_notify() skb allocation

fill_route() stores three components in the skb:

• struct rtmsg
• RTA_DST (u8)
• RTA_OIF (u32)

Therefore, rtm_phonet_notify() should use

NLMSG_ALIGN(sizeof(struct rtmsg)) + nla_total_size(1) + nla_total_size(4)(CVE-2024-36946)

In the Linux kernel, the following vulnerability has been resolved:

m68k: Fix spinlock race in kernel thread creation

Context switching does take care to retain the correct lock owner across the switch from 'prev' to 'next' tasks. This does rely on interrupts remaining disabled for the entire duration of the switch.

This condition is guaranteed for normal process creation and context switching between already running processes, because both 'prev' and 'next' already have interrupts disabled in their saved copies of the status register.

The situation is different for newly created kernel threads. The status register is set to PS_S in copy_thread(), which does leave the IPL at 0. Upon restoring the 'next' thread's status register in switch_to() aka resume(), interrupts then become enabled prematurely. resume() then returns via ret_from_kernel_thread() and schedule_tail() where run queue lock is released (see finish_task_switch() and finish_lock_switch()).

A timer interrupt calling scheduler_tick() before the lock is released in finish_task_switch() will find the lock already taken, with the current task as lock owner. This causes a spinlock recursion warning as reported by Guenter Roeck.

As far as I can ascertain, this race has been opened in commit 533e6903bea0 ("m68k: split ret_from_fork(), simplify kernel_thread()") but I haven't done a detailed study of kernel history so it may well predate that commit.

Interrupts cannot be disabled in the saved status register copy for kernel threads (init will complain about interrupts disabled when finally starting user space). Disable interrupts temporarily when switching the tasks' register sets in resume().

Note that a simple oriw 0x700,%sr after restoring sr is not enough here

• this leaves enough of a race for the 'spinlock recursion' warning to still be observed.

Tested on ARAnyM and qemu (Quadra 800 emulation).(CVE-2024-38613)

In the Linux kernel, the following vulnerability has been resolved:

ipv6: sr: fix missing sk_buff release in seg6_input_core

The seg6_input() function is responsible for adding the SRH into a packet, delegating the operation to the seg6_input_core(). This function uses the skb_cow_head() to ensure that there is sufficient headroom in the sk_buff for accommodating the link-layer header. In the event that the skb_cow_header() function fails, the seg6_input_core() catches the error but it does not release the sk_buff, which will result in a memory leak.

This issue was introduced in commit af3b5158b89d ("ipv6: sr: fix BUG due to headroom too small after SRH push") and persists even after commit 7a3f5b0de364 ("netfilter: add netfilter hooks to SRv6 data plane"), where the entire seg6_input() code was refactored to deal with netfilter hooks.

The proposed patch addresses the identified memory leak by requiring the seg6_input_core() function to release the sk_buff in the event that skb_cow_head() fails.(CVE-2024-39490)

In the Linux kernel, the following vulnerability has been resolved:

crypto: hisilicon/sec - Fix memory leak for sec resource release

The AIV is one of the SEC resources. When releasing resources, it need to release the AIV resources at the same time. Otherwise, memory leakage occurs.

The aiv resource release is added to the sec resource release function.(CVE-2024-41002)

In the Linux kernel, the following vulnerability has been resolved:

ocfs2: add bounds checking to ocfs2_check_dir_entry()

This adds sanity checks for ocfs2_dir_entry to make sure all members of ocfs2_dir_entry don't stray beyond valid memory region.(CVE-2024-41015)

In the Linux kernel, the following vulnerability has been resolved:

hfsplus: fix uninit-value in copy_name

[syzbot reported] BUG: KMSAN: uninit-value in sized_strscpy+0xc4/0x160 sized_strscpy+0xc4/0x160 copy_name+0x2af/0x320 fs/hfsplus/xattr.c:411 hfsplus_listxattr+0x11e9/0x1a50 fs/hfsplus/xattr.c:750 vfs_listxattr fs/xattr.c:493 [inline] listxattr+0x1f3/0x6b0 fs/xattr.c:840 path_listxattr fs/xattr.c:864 [inline] __do_sys_listxattr fs/xattr.c:876 [inline] __se_sys_listxattr fs/xattr.c:873 [inline] __x64_sys_listxattr+0x16b/0x2f0 fs/xattr.c:873 x64_sys_call+0x2ba0/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:195 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at: slab_post_alloc_hook mm/slub.c:3877 [inline] slab_alloc_node mm/slub.c:3918 [inline] kmalloc_trace+0x57b/0xbe0 mm/slub.c:4065 kmalloc include/linux/slab.h:628 [inline] hfsplus_listxattr+0x4cc/0x1a50 fs/hfsplus/xattr.c:699 vfs_listxattr fs/xattr.c:493 [inline] listxattr+0x1f3/0x6b0 fs/xattr.c:840 path_listxattr fs/xattr.c:864 [inline] __do_sys_listxattr fs/xattr.c:876 [inline] __se_sys_listxattr fs/xattr.c:873 [inline] __x64_sys_listxattr+0x16b/0x2f0 fs/xattr.c:873 x64_sys_call+0x2ba0/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:195 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f [Fix] When allocating memory to strbuf, initialize memory to 0.(CVE-2024-41059)

In the Linux kernel, the following vulnerability has been resolved:

s390/sclp: Fix sclp_init() cleanup on failure

If sclp_init() fails it only partially cleans up: if there are multiple failing calls to sclp_init() sclp_state_change_event will be added several times to sclp_reg_list, which results in the following warning:

------------[ cut here ]------------ list_add double add: new=000003ffe1598c10, prev=000003ffe1598bf0, next=000003ffe1598c10. WARNING: CPU: 0 PID: 1 at lib/list_debug.c:35 __list_add_valid_or_report+0xde/0xf8 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.10.0-rc3 Krnl PSW : 0404c00180000000 000003ffe0d6076a (__list_add_valid_or_report+0xe2/0xf8) R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3 ... Call Trace: [<000003ffe0d6076a>] __list_add_valid_or_report+0xe2/0xf8 ([<000003ffe0d60766>] __list_add_valid_or_report+0xde/0xf8) [<000003ffe0a8d37e>] sclp_init+0x40e/0x450 [<000003ffe00009f2>] do_one_initcall+0x42/0x1e0 [<000003ffe15b77a6>] do_initcalls+0x126/0x150 [<000003ffe15b7a0a>] kernel_init_freeable+0x1ba/0x1f8 [<000003ffe0d6650e>] kernel_init+0x2e/0x180 [<000003ffe000301c>] __ret_from_fork+0x3c/0x60 [<000003ffe0d759ca>] ret_from_fork+0xa/0x30

Fix this by removing sclp_state_change_event from sclp_reg_list when sclp_init() fails.(CVE-2024-41068)

In the Linux kernel, the following vulnerability has been resolved:

drm/amd/display: Check pipe offset before setting vblank

pipe_ctx has a size of MAX_PIPES so checking its index before accessing the array.

This fixes an OVERRUN issue reported by Coverity.(CVE-2024-42120)

In the Linux kernel, the following vulnerability has been resolved:

drm/amd/display: Add NULL pointer check for kzalloc

[Why & How] Check return pointer of kzalloc before using it.(CVE-2024-42122)

In the Linux kernel, the following vulnerability has been resolved:

protect the fetch of ->fd[fd] in do_dup2() from mispredictions

both callers have verified that fd is not greater than ->max_fds; however, misprediction might end up with tofree = fdt->fd[fd]; being speculatively executed. That's wrong for the same reasons why it's wrong in close_fd()/file_close_fd_locked(); the same solution applies - array_index_nospec(fd, fdt->max_fds) could differ from fd only in case of speculative execution on mispredicted path.(CVE-2024-42265)

In the Linux kernel, the following vulnerability has been resolved:

net/iucv: fix use after free in iucv_sock_close()

iucv_sever_path() is called from process context and from bh context. iucv->path is used as indicator whether somebody else is taking care of severing the path (or it is already removed / never existed). This needs to be done with atomic compare and swap, otherwise there is a small window where iucv_sock_close() will try to work with a path that has already been severed and freed by iucv_callback_connrej() called by iucv_tasklet_fn().

Example: [452744.123844] Call Trace: [452744.123845] ([<0000001e87f03880>] 0x1e87f03880) [452744.123966] [<00000000d593001e>] iucv_path_sever+0x96/0x138 [452744.124330] [<000003ff801ddbca>] iucv_sever_path+0xc2/0xd0 [af_iucv] [452744.124336] [<000003ff801e01b6>] iucv_sock_close+0xa6/0x310 [af_iucv] [452744.124341] [<000003ff801e08cc>] iucv_sock_release+0x3c/0xd0 [af_iucv] [452744.124345] [<00000000d574794e>] __sock_release+0x5e/0xe8 [452744.124815] [<00000000d5747a0c>] sock_close+0x34/0x48 [452744.124820] [<00000000d5421642>] __fput+0xba/0x268 [452744.124826] [<00000000d51b382c>] task_work_run+0xbc/0xf0 [452744.124832] [<00000000d5145710>] do_notify_resume+0x88/0x90 [452744.124841] [<00000000d5978096>] system_call+0xe2/0x2c8 [452744.125319] Last Breaking-Event-Address: [452744.125321] [<00000000d5930018>] iucv_path_sever+0x90/0x138 [452744.125324] [452744.125325] Kernel panic - not syncing: Fatal exception in interrupt

Note that bh_lock_sock() is not serializing the tasklet context against process context, because the check for sock_owned_by_user() and corresponding handling is missing.

Ideas for a future clean-up patch: A) Correct usage of bh_lock_sock() in tasklet context, as described in Re-enqueue, if needed. This may require adding return values to the tasklet functions and thus changes to all users of iucv.

B) Change iucv tasklet into worker and use only lock_sock() in af_iucv.(CVE-2024-42271)

In the Linux kernel, the following vulnerability has been resolved:

mISDN: Fix a use after free in hfcmulti_tx()

Don't dereference *sp after calling dev_kfree_skb(*sp).(CVE-2024-42280)

In the Linux kernel, the following vulnerability has been resolved:

bpf: Fix a segment issue when downgrading gso_size

Linearize the skb when downgrading gso_size because it may trigger a BUG_ON() later when the skb is segmented as described in [1,2].(CVE-2024-42281)

In the Linux kernel, the following vulnerability has been resolved:

tipc: Return non-zero value from tipc_udp_addr2str() on error

tipc_udp_addr2str() should return non-zero value if the UDP media address is invalid. Otherwise, a buffer overflow access can occur in tipc_media_addr_printf(). Fix this by returning 1 on an invalid UDP media address.(CVE-2024-42284)

In the Linux kernel, the following vulnerability has been resolved:

RDMA/iwcm: Fix a use-after-free related to destroying CM IDs

iw_conn_req_handler() associates a new struct rdma_id_private (conn_id) with an existing struct iw_cm_id (cm_id) as follows:

    conn_id->cm_id.iw = cm_id;
    cm_id->context = conn_id;
    cm_id->cm_handler = cma_iw_handler;

rdma_destroy_id() frees both the cm_id and the struct rdma_id_private. Make sure that cm_work_handler() does not trigger a use-after-free by only freeing of the struct rdma_id_private after all pending work has finished.(CVE-2024-42285)

In the Linux kernel, the following vulnerability has been resolved:

scsi: qla2xxx: Fix for possible memory corruption

Init Control Block is dereferenced incorrectly. Correctly dereference ICB(CVE-2024-42288)

In the Linux kernel, the following vulnerability has been resolved:

f2fs: fix to don't dirty inode for readonly filesystem

syzbot reports f2fs bug as below:

kernel BUG at fs/f2fs/inode.c:933! RIP: 0010:f2fs_evict_inode+0x1576/0x1590 fs/f2fs/inode.c:933 Call Trace: evict+0x2a4/0x620 fs/inode.c:664 dispose_list fs/inode.c:697 [inline] evict_inodes+0x5f8/0x690 fs/inode.c:747 generic_shutdown_super+0x9d/0x2c0 fs/super.c:675 kill_block_super+0x44/0x90 fs/super.c:1667 kill_f2fs_super+0x303/0x3b0 fs/f2fs/super.c:4894 deactivate_locked_super+0xc1/0x130 fs/super.c:484 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1256 task_work_run+0x24a/0x300 kernel/task_work.c:180 ptrace_notify+0x2cd/0x380 kernel/signal.c:2399 ptrace_report_syscall include/linux/ptrace.h:411 [inline] ptrace_report_syscall_exit include/linux/ptrace.h:473 [inline] syscall_exit_work kernel/entry/common.c:251 [inline] syscall_exit_to_user_mode_prepare kernel/entry/common.c:278 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x15c/0x280 kernel/entry/common.c:296 do_syscall_64+0x50/0x110 arch/x86/entry/common.c:88 entry_SYSCALL_64_after_hwframe+0x63/0x6b

The root cause is:

• do_sys_open

• f2fs_lookup

• __f2fs_find_entry

• f2fs_i_depth_write - f2fs_mark_inode_dirty_sync

  • f2fs_dirty_inode
  • set_inode_flag(inode, FI_DIRTY_INODE)

• umount

• kill_f2fs_super

• kill_block_super

• generic_shutdown_super - sync_filesystem : sb is readonly, skip sync_filesystem() - evict_inodes

  • iput
  • f2fs_evict_inode
  • f2fs_bug_on(sbi, is_inode_flag_set(inode, FI_DIRTY_INODE)) : trigger kernel panic

When we try to repair i_current_depth in readonly filesystem, let's skip dirty inode to avoid panic in later f2fs_evict_inode().(CVE-2024-42297)

In the Linux kernel, the following vulnerability has been resolved:

PCI/DPC: Fix use-after-free on concurrent DPC and hot-removal

Keith reports a use-after-free when a DPC event occurs concurrently to hot-removal of the same portion of the hierarchy:

The dpc_handler() awaits readiness of the secondary bus below the Downstream Port where the DPC event occurred. To do so, it polls the config space of the first child device on the secondary bus. If that child device is concurrently removed, accesses to its struct pci_dev cause the kernel to oops.

That's because pci_bridge_wait_for_secondary_bus() neglects to hold a reference on the child device. Before v6.3, the function was only called on resume from system sleep or on runtime resume. Holding a reference wasn't necessary back then because the pciehp IRQ thread could never run concurrently. (On resume from system sleep, IRQs are not enabled until after the resume_noirq phase. And runtime resume is always awaited before a PCI device is removed.)

However starting with v6.3, pci_bridge_wait_for_secondary_bus() is also called on a DPC event. Commit 53b54ad074de ("PCI/DPC: Await readiness of secondary bus after reset"), which introduced that, failed to appreciate that pci_bridge_wait_for_secondary_bus() now needs to hold a reference on the child device because dpc_handler() and pciehp may indeed run concurrently. The commit was backported to v5.10+ stable kernels, so that's the oldest one affected.

Add the missing reference acquisition.

Abridged stack trace:

BUG: unable to handle page fault for address: 00000000091400c0 CPU: 15 PID: 2464 Comm: irq/53-pcie-dpc 6.9.0 RIP: pci_bus_read_config_dword+0x17/0x50 pci_dev_wait() pci_bridge_wait_for_secondary_bus() dpc_reset_link() pcie_do_recovery() dpc_handler()(CVE-2024-42302)

In the Linux kernel, the following vulnerability has been resolved:

ext4: check dot and dotdot of dx_root before making dir indexed

Syzbot reports a issue as follows:

BUG: unable to handle page fault for address: ffffed11022e24fe PGD 23ffee067 P4D 23ffee067 PUD 0 Oops: Oops: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 0 PID: 5079 Comm: syz-executor306 Not tainted 6.10.0-rc5-g55027e689933 #0 Call Trace: <TASK> make_indexed_dir+0xdaf/0x13c0 fs/ext4/namei.c:2341 ext4_add_entry+0x222a/0x25d0 fs/ext4/namei.c:2451 ext4_rename fs/ext4/namei.c:3936 [inline] ext4_rename2+0x26e5/0x4370 fs/ext4/namei.c:4214 [...]

The immediate cause of this problem is that there is only one valid dentry for the block to be split during do_split, so split==0 results in out of bounds accesses to the map triggering the issue.

do_split
  unsigned split
  dx_make_map
   count = 1
  split = count/2 = 0;
  continued = hash2 == map[split - 1].hash;
   ---> map[4294967295]

The maximum length of a filename is 255 and the minimum block size is 1024, so it is always guaranteed that the number of entries is greater than or equal to 2 when do_split() is called.

But syzbot's crafted image has no dot and dotdot in dir, and the dentry distribution in dirblock is as follows:

bus dentry1 hole dentry2 free |xx--|xx-------------|...............|xx-------------|...............| 0 12 (8+248)=256 268 256 524 (8+256)=264 788 236 1024

So when renaming dentry1 increases its name_len length by 1, neither hole nor free is sufficient to hold the new dentry, and make_indexed_dir() is called.

In make_indexed_dir() it is assumed that the first two entries of the dirblock must be dot and dotdot, so bus and dentry1 are left in dx_root because they are treated as dot and dotdot, and only dentry2 is moved to the new leaf block. That's why count is equal to 1.

Therefore add the ext4_check_dx_root() helper function to add more sanity checks to dot and dotdot before starting the conversion to avoid the above issue.(CVE-2024-42305)

In the Linux kernel, the following vulnerability has been resolved:

drm/amd/display: Check for NULL pointer

[why & how] Need to make sure plane_state is initialized before accessing its members.

(cherry picked from commit 295d91cbc700651782a60572f83c24861607b648)(CVE-2024-42308)

In the Linux kernel, the following vulnerability has been resolved:

landlock: Don't lose track of restrictions on cred_transfer

When a process' cred struct is replaced, this almost always invokes the cred_prepare LSM hook; but in one special case (when KEYCTL_SESSION_TO_PARENT updates the parent's credentials), the cred_transfer LSM hook is used instead. Landlock only implements the cred_prepare hook, not cred_transfer, so KEYCTL_SESSION_TO_PARENT causes all information on Landlock restrictions to be lost.

This basically means that a process with the ability to use the fork() and keyctl() syscalls can get rid of all Landlock restrictions on itself.

Fix it by adding a cred_transfer hook that does the same thing as the existing cred_prepare hook. (Implemented by having hook_cred_prepare() call hook_cred_transfer() so that the two functions are less likely to accidentally diverge in the future.)(CVE-2024-42318)

In the Linux kernel, the following vulnerability has been resolved:

kvm: s390: Reject memory region operations for ucontrol VMs

This change rejects the KVM_SET_USER_MEMORY_REGION and KVM_SET_USER_MEMORY_REGION2 ioctls when called on a ucontrol VM. This is necessary since ucontrol VMs have kvm->arch.gmap set to 0 and would thus result in a null pointer dereference further in. Memory management needs to be performed in userspace and using the ioctls KVM_S390_UCAS_MAP and KVM_S390_UCAS_UNMAP.

Also improve s390 specific documentation for KVM_SET_USER_MEMORY_REGION and KVM_SET_USER_MEMORY_REGION2.

frankja@linux.ibm.com: commit message spelling fix, subject prefix fix

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!(CVE-2024-43828)

In the Linux kernel, the following vulnerability has been resolved:

media: mediatek: vcodec: Handle invalid decoder vsi

Handle an invalid decoder vsi in vpu_dec_init to ensure the decoder vsi is valid for future use.(CVE-2024-43831)

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(CVE-2024-43853)

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:

net: usb: qmi_wwan: fix memory leak for not ip packets

Free the unused skb when not ip packets arrive.(CVE-2024-43861)

In the Linux kernel, the following vulnerability has been resolved:

net/mlx5: Always drain health in shutdown callback

There is no point in recovery during device shutdown. if health work started need to wait for it to avoid races and NULL pointer access.

Hence, drain health WQ on shutdown callback.(CVE-2024-43866)

In the Linux kernel, the following vulnerability has been resolved:

wifi: cfg80211: handle 2x996 RU allocation in cfg80211_calculate_bitrate_he()

Currently NL80211_RATE_INFO_HE_RU_ALLOC_2x996 is not handled in cfg80211_calculate_bitrate_he(), leading to below warning:

kernel: invalid HE MCS: bw:6, ru:6 kernel: WARNING: CPU: 0 PID: 2312 at net/wireless/util.c:1501 cfg80211_calculate_bitrate_he+0x22b/0x270 [cfg80211]

Fix it by handling 2x996 RU allocation in the same way as 160 MHz bandwidth.(CVE-2024-43879)

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.(CVE-2024-43882)