Linux

In the Linux kernel, the following vulnerability has been resolved: tracefs: Use generic inode RCU for synchronizing freeing With structure layout randomization enabled for 'struct inode' we need to avoid overlapping any of the RCU-used / initialized-only-once members, e.g. i_lru or i_sb_list to not corrupt related list traversals when making use of the rcu_head. For an unlucky structure layout of 'struct inode' we may end up with the following splat when running the ftrace selftests: [<...>] list_del corruption, ffff888103ee2cb0->next (tracefs_inode_cache+0x0/0x4e0 [slab object]) is NULL (prev is tracefs_inode_cache+0x78/0x4e0 [slab object]) [<...>] ------------[ cut here ]------------ [<...>] kernel BUG at lib/list_debug.c:54! [<...>] invalid opcode: 0000 [#1] PREEMPT SMP KASAN [<...>] CPU: 3 PID: 2550 Comm: mount Tainted: G N 6.8.12-grsec+ #122 ed2f536ca62f28b087b90e3cc906a8d25b3ddc65 [<...>] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 [<...>] RIP: 0010:[<ffffffff84656018>] __list_del_entry_valid_or_report+0x138/0x3e0 [<...>] Code: 48 b8 99 fb 65 f2 ff ff ff ff e9 03 5c d9 fc cc 48 b8 99 fb 65 f2 ff ff ff ff e9 33 5a d9 fc cc 48 b8 99 fb 65 f2 ff ff ff ff <0f> 0b 4c 89 e9 48 89 ea 48 89 ee 48 c7 c7 60 8f dd 89 31 c0 e8 2f [<...>] RSP: 0018:fffffe80416afaf0 EFLAGS: 00010283 [<...>] RAX: 0000000000000098 RBX: ffff888103ee2cb0 RCX: 0000000000000000 [<...>] RDX: ffffffff84655fe8 RSI: ffffffff89dd8b60 RDI: 0000000000000001 [<...>] RBP: ffff888103ee2cb0 R08: 0000000000000001 R09: fffffbd0082d5f25 [<...>] R10: fffffe80416af92f R11: 0000000000000001 R12: fdf99c16731d9b6d [<...>] R13: 0000000000000000 R14: ffff88819ad4b8b8 R15: 0000000000000000 [<...>] RBX: tracefs_inode_cache+0x0/0x4e0 [slab object] [<...>] RDX: __list_del_entry_valid_or_report+0x108/0x3e0 [<...>] RSI: __func__.47+0x4340/0x4400 [<...>] RBP: tracefs_inode_cache+0x0/0x4e0 [slab object] [<...>] RSP: process kstack fffffe80416afaf0+0x7af0/0x8000 [mount 2550 2550] [<...>] R09: kasan shadow of process kstack fffffe80416af928+0x7928/0x8000 [mount 2550 2550] [<...>] R10: process kstack fffffe80416af92f+0x792f/0x8000 [mount 2550 2550] [<...>] R14: tracefs_inode_cache+0x78/0x4e0 [slab object] [<...>] FS: 00006dcb380c1840(0000) GS:ffff8881e0600000(0000) knlGS:0000000000000000 [<...>] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [<...>] CR2: 000076ab72b30e84 CR3: 000000000b088004 CR4: 0000000000360ef0 shadow CR4: 0000000000360ef0 [<...>] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [<...>] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [<...>] ASID: 0003 [<...>] Stack: [<...>] ffffffff818a2315 00000000f5c856ee ffffffff896f1840 ffff888103ee2cb0 [<...>] ffff88812b6b9750 0000000079d714b6 fffffbfff1e9280b ffffffff8f49405f [<...>] 0000000000000001 0000000000000000 ffff888104457280 ffffffff8248b392 [<...>] Call Trace: [<...>] <TASK> [<...>] [<ffffffff818a2315>] ? lock_release+0x175/0x380 fffffe80416afaf0 [<...>] [<ffffffff8248b392>] list_lru_del+0x152/0x740 fffffe80416afb48 [<...>] [<ffffffff8248ba93>] list_lru_del_obj+0x113/0x280 fffffe80416afb88 [<...>] [<ffffffff8940fd19>] ? _atomic_dec_and_lock+0x119/0x200 fffffe80416afb90 [<...>] [<ffffffff8295b244>] iput_final+0x1c4/0x9a0 fffffe80416afbb8 [<...>] [<ffffffff8293a52b>] dentry_unlink_inode+0x44b/0xaa0 fffffe80416afbf8 [<...>] [<ffffffff8293fefc>] __dentry_kill+0x23c/0xf00 fffffe80416afc40 [<...>] [<ffffffff8953a85f>] ? __this_cpu_preempt_check+0x1f/0xa0 fffffe80416afc48 [<...>] [<ffffffff82949ce5>] ? shrink_dentry_list+0x1c5/0x760 fffffe80416afc70 [<...>] [<ffffffff82949b71>] ? shrink_dentry_list+0x51/0x760 fffffe80416afc78 [<...>] [<ffffffff82949da8>] shrink_dentry_list+0x288/0x760 fffffe80416afc80 [<...>] [<ffffffff8294ae75>] shrink_dcache_sb+0x155/0x420 fffffe80416afcc8 [<...>] [<ffffffff8953a7c3>] ? debug_smp_processor_id+0x23/0xa0 fffffe80416afce0 [<...>] [<ffffffff8294ad20>] ? do_one_tre ---truncated---Show less

In the Linux kernel, the following vulnerability has been resolved: sched/smt: Fix unbalance sched_smt_present dec/inc I got the following warn report while doing stress test: jump label: negative count! WARNING: CPU: 3 PID: 38 at kernel/jump_label.c:263 static_key_slow_try_dec+0x9d/0xb0 Call Trace: <TASK> __static_key_slow_dec_cpuslocked+0x16/0x70 sched_cpu_deactivate+0x26e/0x2a0 cpuhp_invoke_callback+0x3ad/0x10d0 cpuhp_thread_fun+0x3f5/0x680 smpboot_thread_fn+0x56d/0x8d0 kthread+0x309/0x400 ret_from_fork+0x41/0x70 ret_from_fork_asm+0x1b/0x30 </TASK> Because when cpuset_cpu_inactive() fails in sched_cpu_deactivate(), the cpu offline failed, but sched_smt_present is decremented before calling sched_cpu_deactivate(), it leads to unbalanced dec/inc, so fix it by incrementing sched_smt_present in the error path.Show less

In the Linux kernel, the following vulnerability has been resolved: xen: privcmd: Switch from mutex to spinlock for irqfds irqfd_wakeup() gets EPOLLHUP, when it is called by eventfd_release() by way of wake_up_poll(&ctx->wqh, EPOLLHUP), which gets called under spin_lock_irqsave(). We can't use a mutex here as it will lead to a deadlock. Fix it by switching over to a spin lock.Show less

In the Linux kernel, the following vulnerability has been resolved: drm/xe/preempt_fence: enlarge the fence critical section It is really easy to introduce subtle deadlocks in preempt_fence_work_func() since we operate on single global ordered-wq for signalling our preempt fences behind the scenes, so even though we signal a particular fence, everything in the callback should be in the fence critical section, since blocking in the callback will prevent other published fences from signalling. If we enlarge the fence critical section to cover the entire callback, then lockdep should be able to understand this better, and complain if we grab a sensitive lock like vm->lock, which is also held when waiting on preempt fences.Show less

In the Linux kernel, the following vulnerability has been resolved: ALSA: line6: Fix racy access to midibuf There can be concurrent accesses to line6 midibuf from both the URB completion callback and the rawmidi API access. This could be a cause of KMSAN warning triggered by syzkaller below (so put as reported-by here). This patch protects the midibuf call of the former code path with a spinlock for avoiding the possible races.Show less

In the Linux kernel, the following vulnerability has been resolved: scsi: ufs: core: Fix deadlock during RTC update There is a deadlock when runtime suspend waits for the flush of RTC work, and the RTC work calls ufshcd_rpm_get_sync() to wait for runtime resume. Here is deadlock backtrace: kworker/0:1 D 4892.876354 10 10971 4859 0x4208060 0x8 10 0 120 670730152367 ptr f0ffff80c2e40000 0 1 0x00000001 0x000000ff 0x000000ff 0x000000ff <ffffffee5e71ddb0> __switch_to+0x1a8/0x2d4 <ffffffee5e71e604> __schedule+0x684/0xa98 <ffffffee5e71ea60> schedule+0x48/0xc8 <ffffffee5e725f78> schedule_timeout+0x48/0x170 <ffffffee5e71fb74> do_wait_for_common+0x108/0x1b0 <ffffffee5e71efe0> wait_for_completion+0x44/0x60 <ffffffee5d6de968> __flush_work+0x39c/0x424 <ffffffee5d6decc0> __cancel_work_sync+0xd8/0x208 <ffffffee5d6dee2c> cancel_delayed_work_sync+0x14/0x28 <ffffffee5e2551b8> __ufshcd_wl_suspend+0x19c/0x480 <ffffffee5e255fb8> ufshcd_wl_runtime_suspend+0x3c/0x1d4 <ffffffee5dffd80c> scsi_runtime_suspend+0x78/0xc8 <ffffffee5df93580> __rpm_callback+0x94/0x3e0 <ffffffee5df90b0c> rpm_suspend+0x2d4/0x65c <ffffffee5df91448> __pm_runtime_suspend+0x80/0x114 <ffffffee5dffd95c> scsi_runtime_idle+0x38/0x6c <ffffffee5df912f4> rpm_idle+0x264/0x338 <ffffffee5df90f14> __pm_runtime_idle+0x80/0x110 <ffffffee5e24ce44> ufshcd_rtc_work+0x128/0x1e4 <ffffffee5d6e3a40> process_one_work+0x26c/0x650 <ffffffee5d6e65c8> worker_thread+0x260/0x3d8 <ffffffee5d6edec8> kthread+0x110/0x134 <ffffffee5d616b18> ret_from_fork+0x10/0x20 Skip updating RTC if RPM state is not RPM_ACTIVE.Show less

In the Linux kernel, the following vulnerability has been resolved: serial: sc16is7xx: fix TX fifo corruption Sometimes, when a packet is received on channel A at almost the same time as a packet is about to be transmitted on channel B, we observe with a logic analyzer that the received packet on channel A is transmitted on channel B. In other words, the Tx buffer data on channel B is corrupted with data from channel A. The problem appeared since commit 4409df5866b7 ("serial: sc16is7xx: change EFR lock to operate on each channels"), which changed the EFR locking to operate on each channel instead of chip-wise. This commit has introduced a regression, because the EFR lock is used not only to protect the EFR registers access, but also, in a very obscure and undocumented way, to protect access to the data buffer, which is shared by the Tx and Rx handlers, but also by each channel of the IC. Fix this regression first by switching to kfifo_out_linear_ptr() in sc16is7xx_handle_tx() to eliminate the need for a shared Rx/Tx buffer. Secondly, replace the chip-wise Rx buffer with a separate Rx buffer for each channel.Show less

In the Linux kernel, the following vulnerability has been resolved: serial: sc16is7xx: fix invalid FIFO access with special register set When enabling access to the special register set, Receiver time-out and RHR interrupts can happen. In this case, the IRQ handler will try to read from the FIFO thru the RHR register at address 0x00, but address 0x00 is mapped to DLL register, resulting in erroneous FIFO reading. Call graph example: sc16is7xx_startup(): entry sc16is7xx_ms_proc(): entry sc16is7xx_set_termios(): entry sc16is7xx_set_baud(): DLH/DLL = $009C --> access special register set sc16is7xx_port_irq() entry --> IIR is 0x0C sc16is7xx_handle_rx() entry sc16is7xx_fifo_read(): --> unable to access FIFO (RHR) because it is mapped to DLL (LCR=LCR_CONF_MODE_A) sc16is7xx_set_baud(): exit --> Restore access to general register set Fix the problem by claiming the efr_lock mutex when accessing the Special register set.Show less

In the Linux kernel, the following vulnerability has been resolved: parisc: fix a possible DMA corruption ARCH_DMA_MINALIGN was defined as 16 - this is too small - it may be possible that two unrelated 16-byte allocations share a cache line. If one of these allocations is written using DMA and the other is written using cached write, the value that was written with DMA may be corrupted. This commit changes ARCH_DMA_MINALIGN to be 128 on PA20 and 32 on PA1.1 - that's the largest possible cache line size. As different parisc microarchitectures have different cache line size, we define arch_slab_minalign(), cache_line_size() and dma_get_cache_alignment() so that the kernel may tune slab cache parameters dynamically, based on the detected cache line size.Show less

In the Linux kernel, the following vulnerability has been resolved: x86/mtrr: Check if fixed MTRRs exist before saving them MTRRs have an obsolete fixed variant for fine grained caching control of the 640K-1MB region that uses separate MSRs. This fixed variant has a separate capability bit in the MTRR capability MSR. So far all x86 CPUs which support MTRR have this separate bit set, so it went unnoticed that mtrr_save_state() does not check the capability bit before accessing the fixed MTRR MSRs. Though on a CPU that does not support the fixed MTRR capability this results in a #GP. The #GP itself is harmless because the RDMSR fault is handled gracefully, but results in a WARN_ON(). Add the missing capability check to prevent this.Show less

In the Linux kernel, the following vulnerability has been resolved: fuse: Initialize beyond-EOF page contents before setting uptodate fuse_notify_store(), unlike fuse_do_readpage(), does not enable page zeroing (because it can be used to change partial page contents). So fuse_notify_store() must be more careful to fully initialize page contents (including parts of the page that are beyond end-of-file) before marking the page uptodate. The current code can leave beyond-EOF page contents uninitialized, which makes these uninitialized page contents visible to userspace via mmap(). This is an information leak, but only affects systems which do not enable init-on-alloc (via CONFIG_INIT_ON_ALLOC_DEFAULT_ON=y or the corresponding kernel command line parameter).Show less

In the Linux kernel, the following vulnerability has been resolved: kcm: Serialise kcm_sendmsg() for the same socket. syzkaller reported UAF in kcm_release(). [0] The scenario is 1. Thread A builds a skb with MSG_MORE and sets kcm->seq_skb. 2. Thread A resumes building skb from kcm->seq_skb but is blocked by sk_stream_wait_memory() 3. Thread B calls sendmsg() concurrently, finishes building kcm->seq_skb and puts the skb to the write queue 4. Thread A faces an error and finally frees skb that is already in the write queue 5. kcm_release() does double-free the skb in the write queue When a thread is building a MSG_MORE skb, another thread must not touch it. Let's add a per-sk mutex and serialise kcm_sendmsg(). [0]: BUG: KASAN: slab-use-after-free in __skb_unlink include/linux/skbuff.h:2366 [inline] BUG: KASAN: slab-use-after-free in __skb_dequeue include/linux/skbuff.h:2385 [inline] BUG: KASAN: slab-use-after-free in __skb_queue_purge_reason include/linux/skbuff.h:3175 [inline] BUG: KASAN: slab-use-after-free in __skb_queue_purge include/linux/skbuff.h:3181 [inline] BUG: KASAN: slab-use-after-free in kcm_release+0x170/0x4c8 net/kcm/kcmsock.c:1691 Read of size 8 at addr ffff0000ced0fc80 by task syz-executor329/6167 CPU: 1 PID: 6167 Comm: syz-executor329 Tainted: G B 6.8.0-rc5-syzkaller-g9abbc24128bc #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call trace: dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:291 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:298 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:377 [inline] print_report+0x178/0x518 mm/kasan/report.c:488 kasan_report+0xd8/0x138 mm/kasan/report.c:601 __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381 __skb_unlink include/linux/skbuff.h:2366 [inline] __skb_dequeue include/linux/skbuff.h:2385 [inline] __skb_queue_purge_reason include/linux/skbuff.h:3175 [inline] __skb_queue_purge include/linux/skbuff.h:3181 [inline] kcm_release+0x170/0x4c8 net/kcm/kcmsock.c:1691 __sock_release net/socket.c:659 [inline] sock_close+0xa4/0x1e8 net/socket.c:1421 __fput+0x30c/0x738 fs/file_table.c:376 ____fput+0x20/0x30 fs/file_table.c:404 task_work_run+0x230/0x2e0 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x618/0x1f64 kernel/exit.c:871 do_group_exit+0x194/0x22c kernel/exit.c:1020 get_signal+0x1500/0x15ec kernel/signal.c:2893 do_signal+0x23c/0x3b44 arch/arm64/kernel/signal.c:1249 do_notify_resume+0x74/0x1f4 arch/arm64/kernel/entry-common.c:148 exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:169 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:178 [inline] el0_svc+0xac/0x168 arch/arm64/kernel/entry-common.c:713 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 Allocated by task 6166: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:68 kasan_save_alloc_info+0x70/0x84 mm/kasan/generic.c:626 unpoison_slab_object mm/kasan/common.c:314 [inline] __kasan_slab_alloc+0x74/0x8c mm/kasan/common.c:340 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3813 [inline] slab_alloc_node mm/slub.c:3860 [inline] kmem_cache_alloc_node+0x204/0x4c0 mm/slub.c:3903 __alloc_skb+0x19c/0x3d8 net/core/skbuff.c:641 alloc_skb include/linux/skbuff.h:1296 [inline] kcm_sendmsg+0x1d3c/0x2124 net/kcm/kcmsock.c:783 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] sock_sendmsg+0x220/0x2c0 net/socket.c:768 splice_to_socket+0x7cc/0xd58 fs/splice.c:889 do_splice_from fs/splice.c:941 [inline] direct_splice_actor+0xec/0x1d8 fs/splice.c:1164 splice_direct_to_actor+0x438/0xa0c fs/splice.c:1108 do_splice_direct_actor ---truncated---Show less

In the Linux kernel, the following vulnerability has been resolved: sched: Fix yet more sched_fork() races Where commit 4ef0c5c6b5ba ("kernel/sched: Fix sched_fork() access an invalid sched_task_group") fixed a fork race vs cgroup, it opened up a race vs syscalls by not placing the task on the runqueue before it gets exposed through the pidhash. Commit 13765de8148f ("sched/fair: Fix fault in reweight_entity") is trying to fix a single instance of this, instead fix the whole class of issues, effectively reverting this commit.Show less

In the Linux kernel, the following vulnerability has been resolved: netfilter: ctnetlink: use helper function to calculate expect ID Delete expectation path is missing a call to the nf_expect_get_id() helper function to calculate the expectation ID, otherwise LSB of the expectation object address is leaked to userspace.Show less

In the Linux kernel, the following vulnerability has been resolved: tcp: add sanity tests to TCP_QUEUE_SEQ Qingyu Li reported a syzkaller bug where the repro changes RCV SEQ _after_ restoring data in the receive queue. mprotect(0x4aa000, 12288, PROT_READ) = 0 mmap(0x1ffff000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x1ffff000 mmap(0x20000000, 16777216, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x20000000 mmap(0x21000000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x21000000 socket(AF_INET6, SOCK_STREAM, IPPROTO_IP) = 3 setsockopt(3, SOL_TCP, TCP_REPAIR, [1], 4) = 0 connect(3, {sa_family=AF_INET6, sin6_port=htons(0), sin6_flowinfo=htonl(0), inet_pton(AF_INET6, "::1", &sin6_addr), sin6_scope_id=0}, 28) = 0 setsockopt(3, SOL_TCP, TCP_REPAIR_QUEUE, [1], 4) = 0 sendmsg(3, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="0x0000000000000003\0\0", iov_len=20}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 20 setsockopt(3, SOL_TCP, TCP_REPAIR, [0], 4) = 0 setsockopt(3, SOL_TCP, TCP_QUEUE_SEQ, [128], 4) = 0 recvfrom(3, NULL, 20, 0, NULL, NULL) = -1 ECONNRESET (Connection reset by peer) syslog shows: [ 111.205099] TCP recvmsg seq # bug 2: copied 80, seq 0, rcvnxt 80, fl 0 [ 111.207894] WARNING: CPU: 1 PID: 356 at net/ipv4/tcp.c:2343 tcp_recvmsg_locked+0x90e/0x29a0 This should not be allowed. TCP_QUEUE_SEQ should only be used when queues are empty. This patch fixes this case, and the tx path as well.Show less

In the Linux kernel, the following vulnerability has been resolved: mm: gup: stop abusing try_grab_folio A kernel warning was reported when pinning folio in CMA memory when launching SEV virtual machine. The splat looks like: [ 464.325306] WARNING: CPU: 13 PID: 6734 at mm/gup.c:1313 __get_user_pages+0x423/0x520 [ 464.325464] CPU: 13 PID: 6734 Comm: qemu-kvm Kdump: loaded Not tainted 6.6.33+ #6 [ 464.325477] RIP: 0010:__get_user_pages+0x423/0x520 [ 464.325515] Call Trace: [ 464.325520] <TASK> [ 464.325523] ? __get_user_pages+0x423/0x520 [ 464.325528] ? __warn+0x81/0x130 [ 464.325536] ? __get_user_pages+0x423/0x520 [ 464.325541] ? report_bug+0x171/0x1a0 [ 464.325549] ? handle_bug+0x3c/0x70 [ 464.325554] ? exc_invalid_op+0x17/0x70 [ 464.325558] ? asm_exc_invalid_op+0x1a/0x20 [ 464.325567] ? __get_user_pages+0x423/0x520 [ 464.325575] __gup_longterm_locked+0x212/0x7a0 [ 464.325583] internal_get_user_pages_fast+0xfb/0x190 [ 464.325590] pin_user_pages_fast+0x47/0x60 [ 464.325598] sev_pin_memory+0xca/0x170 [kvm_amd] [ 464.325616] sev_mem_enc_register_region+0x81/0x130 [kvm_amd] Per the analysis done by yangge, when starting the SEV virtual machine, it will call pin_user_pages_fast(..., FOLL_LONGTERM, ...) to pin the memory. But the page is in CMA area, so fast GUP will fail then fallback to the slow path due to the longterm pinnalbe check in try_grab_folio(). The slow path will try to pin the pages then migrate them out of CMA area. But the slow path also uses try_grab_folio() to pin the page, it will also fail due to the same check then the above warning is triggered. In addition, the try_grab_folio() is supposed to be used in fast path and it elevates folio refcount by using add ref unless zero. We are guaranteed to have at least one stable reference in slow path, so the simple atomic add could be used. The performance difference should be trivial, but the misuse may be confusing and misleading. Redefined try_grab_folio() to try_grab_folio_fast(), and try_grab_page() to try_grab_folio(), and use them in the proper paths. This solves both the abuse and the kernel warning. The proper naming makes their usecase more clear and should prevent from abusing in the future. peterx said: : The user will see the pin fails, for gpu-slow it further triggers the WARN : right below that failure (as in the original report): : : folio = try_grab_folio(page, page_increm - 1, : foll_flags); : if (WARN_ON_ONCE(!folio)) { <------------------------ here : /* : * Release the 1st page ref if the : * folio is problematic, fail hard. : */ : gup_put_folio(page_folio(page), 1, : foll_flags); : ret = -EFAULT; : goto out; : } [1] https://lore.kernel.org/linux-mm/1719478388-31917-1-git-send-email-yangge1116@126.com/ [shy828301@gmail.com: fix implicit declaration of function try_grab_folio_fast]Show less

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to do sanity check on F2FS_INLINE_DATA flag in inode during GC syzbot reports a f2fs bug as below: ------------[ cut here ]------------ kernel BUG at fs/f2fs/inline.c:258! CPU: 1 PID: 34 Comm: kworker/u8:2 Not tainted 6.9.0-rc6-syzkaller-00012-g9e4bc4bcae01 #0 RIP: 0010:f2fs_write_inline_data+0x781/0x790 fs/f2fs/inline.c:258 Call Trace: f2fs_write_single_data_page+0xb65/0x1d60 fs/f2fs/data.c:2834 f2fs_write_cache_pages fs/f2fs/data.c:3133 [inline] __f2fs_write_data_pages fs/f2fs/data.c:3288 [inline] f2fs_write_data_pages+0x1efe/0x3a90 fs/f2fs/data.c:3315 do_writepages+0x35b/0x870 mm/page-writeback.c:2612 __writeback_single_inode+0x165/0x10b0 fs/fs-writeback.c:1650 writeback_sb_inodes+0x905/0x1260 fs/fs-writeback.c:1941 wb_writeback+0x457/0xce0 fs/fs-writeback.c:2117 wb_do_writeback fs/fs-writeback.c:2264 [inline] wb_workfn+0x410/0x1090 fs/fs-writeback.c:2304 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa12/0x17c0 kernel/workqueue.c:3335 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 kthread+0x2f2/0x390 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 The root cause is: inline_data inode can be fuzzed, so that there may be valid blkaddr in its direct node, once f2fs triggers background GC to migrate the block, it will hit f2fs_bug_on() during dirty page writeback. Let's add sanity check on F2FS_INLINE_DATA flag in inode during GC, so that, it can forbid migrating inline_data inode's data block for fixing.Show less

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to cover read extent cache access with lock syzbot reports a f2fs bug as below: BUG: KASAN: slab-use-after-free in sanity_check_extent_cache+0x370/0x410 fs/f2fs/extent_cache.c:46 Read of size 4 at addr ffff8880739ab220 by task syz-executor200/5097 CPU: 0 PID: 5097 Comm: syz-executor200 Not tainted 6.9.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 sanity_check_extent_cache+0x370/0x410 fs/f2fs/extent_cache.c:46 do_read_inode fs/f2fs/inode.c:509 [inline] f2fs_iget+0x33e1/0x46e0 fs/f2fs/inode.c:560 f2fs_nfs_get_inode+0x74/0x100 fs/f2fs/super.c:3237 generic_fh_to_dentry+0x9f/0xf0 fs/libfs.c:1413 exportfs_decode_fh_raw+0x152/0x5f0 fs/exportfs/expfs.c:444 exportfs_decode_fh+0x3c/0x80 fs/exportfs/expfs.c:584 do_handle_to_path fs/fhandle.c:155 [inline] handle_to_path fs/fhandle.c:210 [inline] do_handle_open+0x495/0x650 fs/fhandle.c:226 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f We missed to cover sanity_check_extent_cache() w/ extent cache lock, so, below race case may happen, result in use after free issue. - f2fs_iget - do_read_inode - f2fs_init_read_extent_tree : add largest extent entry in to cache - shrink - f2fs_shrink_read_extent_tree - __shrink_extent_tree - __detach_extent_node : drop largest extent entry - sanity_check_extent_cache : access et->largest w/o lock let's refactor sanity_check_extent_cache() to avoid extent cache access and call it before f2fs_init_read_extent_tree() to fix this issue.Show less

In the Linux kernel, the following vulnerability has been resolved: fou: remove warn in gue_gro_receive on unsupported protocol Drop the WARN_ON_ONCE inn gue_gro_receive if the encapsulated type is not known or does not have a GRO handler. Such a packet is easily constructed. Syzbot generates them and sets off this warning. Remove the warning as it is expected and not actionable. The warning was previously reduced from WARN_ON to WARN_ON_ONCE in commit 270136613bf7 ("fou: Do WARN_ON_ONCE in gue_gro_receive for bad proto callbacks").Show less