In the Linux kernel, the following vulnerability has been resolved: io_uring: check for non-NULL file pointer in io_file_can_poll() In earlier kernels, it was possible to trigger a NULL pointer dereference off the forced async preparation path, if no file had been assigned. The trace leading to that looks as follows: BUG: kernel NULL pointer dereference, address: 00000000000000b0 PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP CPU: 67 PID: 1633 Comm: buf-ring-invali Not tainted 6.8.0-rc3+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS unknown 2/2/2022 RIP: 0010:io_buffer_select+0xc3/0x210 Code: 00 00 48 39 d1 0f 82 ae 00 00 00 48 81 4b 48 00 00 01 00 48 89 73 70 0f b7 50 0c 66 89 53 42 85 ed 0f 85 d2 00 00 00 48 8b 13 <48> 8b 92 b0 00 00 00 48 83 7a 40 00 0f 84 21 01 00 00 4c 8b 20 5b RSP: 0018:ffffb7bec38c7d88 EFLAGS: 00010246 RAX: ffff97af2be61000 RBX: ffff97af234f1700 RCX: 0000000000000040 RDX: 0000000000000000 RSI: ffff97aecfb04820 RDI: ffff97af234f1700 RBP: 0000000000000000 R08: 0000000000200030 R09: 0000000000000020 R10: ffffb7bec38c7dc8 R11: 000000000000c000 R12: ffffb7bec38c7db8 R13: ffff97aecfb05800 R14: ffff97aecfb05800 R15: ffff97af2be5e000 FS: 00007f852f74b740(0000) GS:ffff97b1eeec0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000b0 CR3: 000000016deab005 CR4: 0000000000370ef0 Call Trace: <TASK> ? __die+0x1f/0x60 ? page_fault_oops+0x14d/0x420 ? do_user_addr_fault+0x61/0x6a0 ? exc_page_fault+0x6c/0x150 ? asm_exc_page_fault+0x22/0x30 ? io_buffer_select+0xc3/0x210 __io_import_iovec+0xb5/0x120 io_readv_prep_async+0x36/0x70 io_queue_sqe_fallback+0x20/0x260 io_submit_sqes+0x314/0x630 __do_sys_io_uring_enter+0x339/0xbc0 ? __do_sys_io_uring_register+0x11b/0xc50 ? vm_mmap_pgoff+0xce/0x160 do_syscall_64+0x5f/0x180 entry_SYSCALL_64_after_hwframe+0x46/0x4e RIP: 0033:0x55e0a110a67e Code: ba cc 00 00 00 45 31 c0 44 0f b6 92 d0 00 00 00 31 d2 41 b9 08 00 00 00 41 83 e2 01 41 c1 e2 04 41 09 c2 b8 aa 01 00 00 0f 05 <c3> 90 89 30 eb a9 0f 1f 40 00 48 8b 42 20 8b 00 a8 06 75 af 85 f6 because the request is marked forced ASYNC and has a bad file fd, and hence takes the forced async prep path. Current kernels with the request async prep cleaned up can no longer hit this issue, but for ease of backporting, let's add this safety check in here too as it really doesn't hurt. For both cases, this will inevitably end with a CQE posted with -EBADF.

In the Linux kernel, the following vulnerability has been resolved: net/9p: fix uninit-value in p9_client_rpc() Syzbot with the help of KMSAN reported the following error: BUG: KMSAN: uninit-value in trace_9p_client_res include/trace/events/9p.h:146 [inline] BUG: KMSAN: uninit-value in p9_client_rpc+0x1314/0x1340 net/9p/client.c:754 trace_9p_client_res include/trace/events/9p.h:146 [inline] p9_client_rpc+0x1314/0x1340 net/9p/client.c:754 p9_client_create+0x1551/0x1ff0 net/9p/client.c:1031 v9fs_session_init+0x1b9/0x28e0 fs/9p/v9fs.c:410 v9fs_mount+0xe2/0x12b0 fs/9p/vfs_super.c:122 legacy_get_tree+0x114/0x290 fs/fs_context.c:662 vfs_get_tree+0xa7/0x570 fs/super.c:1797 do_new_mount+0x71f/0x15e0 fs/namespace.c:3352 path_mount+0x742/0x1f20 fs/namespace.c:3679 do_mount fs/namespace.c:3692 [inline] __do_sys_mount fs/namespace.c:3898 [inline] __se_sys_mount+0x725/0x810 fs/namespace.c:3875 __x64_sys_mount+0xe4/0x150 fs/namespace.c:3875 do_syscall_64+0xd5/0x1f0 entry_SYSCALL_64_after_hwframe+0x6d/0x75 Uninit was created at: __alloc_pages+0x9d6/0xe70 mm/page_alloc.c:4598 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] alloc_slab_page mm/slub.c:2175 [inline] allocate_slab mm/slub.c:2338 [inline] new_slab+0x2de/0x1400 mm/slub.c:2391 ___slab_alloc+0x1184/0x33d0 mm/slub.c:3525 __slab_alloc mm/slub.c:3610 [inline] __slab_alloc_node mm/slub.c:3663 [inline] slab_alloc_node mm/slub.c:3835 [inline] kmem_cache_alloc+0x6d3/0xbe0 mm/slub.c:3852 p9_tag_alloc net/9p/client.c:278 [inline] p9_client_prepare_req+0x20a/0x1770 net/9p/client.c:641 p9_client_rpc+0x27e/0x1340 net/9p/client.c:688 p9_client_create+0x1551/0x1ff0 net/9p/client.c:1031 v9fs_session_init+0x1b9/0x28e0 fs/9p/v9fs.c:410 v9fs_mount+0xe2/0x12b0 fs/9p/vfs_super.c:122 legacy_get_tree+0x114/0x290 fs/fs_context.c:662 vfs_get_tree+0xa7/0x570 fs/super.c:1797 do_new_mount+0x71f/0x15e0 fs/namespace.c:3352 path_mount+0x742/0x1f20 fs/namespace.c:3679 do_mount fs/namespace.c:3692 [inline] __do_sys_mount fs/namespace.c:3898 [inline] __se_sys_mount+0x725/0x810 fs/namespace.c:3875 __x64_sys_mount+0xe4/0x150 fs/namespace.c:3875 do_syscall_64+0xd5/0x1f0 entry_SYSCALL_64_after_hwframe+0x6d/0x75 If p9_check_errors() fails early in p9_client_rpc(), req->rc.tag will not be properly initialized. However, trace_9p_client_res() ends up trying to print it out anyway before p9_client_rpc() finishes. Fix this issue by assigning default values to p9_fcall fields such as 'tag' and (just in case KMSAN unearths something new) 'id' during the tag allocation stage.

In the Linux kernel, the following vulnerability has been resolved: ext4: fix mb_cache_entry's e_refcnt leak in ext4_xattr_block_cache_find() Syzbot reports a warning as follows: ============================================ WARNING: CPU: 0 PID: 5075 at fs/mbcache.c:419 mb_cache_destroy+0x224/0x290 Modules linked in: CPU: 0 PID: 5075 Comm: syz-executor199 Not tainted 6.9.0-rc6-gb947cc5bf6d7 RIP: 0010:mb_cache_destroy+0x224/0x290 fs/mbcache.c:419 Call Trace: <TASK> ext4_put_super+0x6d4/0xcd0 fs/ext4/super.c:1375 generic_shutdown_super+0x136/0x2d0 fs/super.c:641 kill_block_super+0x44/0x90 fs/super.c:1675 ext4_kill_sb+0x68/0xa0 fs/ext4/super.c:7327 [...] ============================================ This is because when finding an entry in ext4_xattr_block_cache_find(), if ext4_sb_bread() returns -ENOMEM, the ce's e_refcnt, which has already grown in the __entry_find(), won't be put away, and eventually trigger the above issue in mb_cache_destroy() due to reference count leakage. So call mb_cache_entry_put() on the -ENOMEM error branch as a quick fix.

In the Linux kernel, the following vulnerability has been resolved: s390/ap: Fix crash in AP internal function modify_bitmap() A system crash like this Failing address: 200000cb7df6f000 TEID: 200000cb7df6f403 Fault in home space mode while using kernel ASCE. AS:00000002d71bc007 R3:00000003fe5b8007 S:000000011a446000 P:000000015660c13d Oops: 0038 ilc:3 [#1] PREEMPT SMP Modules linked in: mlx5_ib ... CPU: 8 PID: 7556 Comm: bash Not tainted 6.9.0-rc7 #8 Hardware name: IBM 3931 A01 704 (LPAR) Krnl PSW : 0704e00180000000 0000014b75e7b606 (ap_parse_bitmap_str+0x10e/0x1f8) R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3 Krnl GPRS: 0000000000000001 ffffffffffffffc0 0000000000000001 00000048f96b75d3 000000cb00000100 ffffffffffffffff ffffffffffffffff 000000cb7df6fce0 000000cb7df6fce0 00000000ffffffff 000000000000002b 00000048ffffffff 000003ff9b2dbc80 200000cb7df6fcd8 0000014bffffffc0 000000cb7df6fbc8 Krnl Code: 0000014b75e7b5fc: a7840047 brc 8,0000014b75e7b68a 0000014b75e7b600: 18b2 lr %r11,%r2 #0000014b75e7b602: a7f4000a brc 15,0000014b75e7b616 >0000014b75e7b606: eb22d00000e6 laog %r2,%r2,0(%r13) 0000014b75e7b60c: a7680001 lhi %r6,1 0000014b75e7b610: 187b lr %r7,%r11 0000014b75e7b612: 84960021 brxh %r9,%r6,0000014b75e7b654 0000014b75e7b616: 18e9 lr %r14,%r9 Call Trace: [<0000014b75e7b606>] ap_parse_bitmap_str+0x10e/0x1f8 ([<0000014b75e7b5dc>] ap_parse_bitmap_str+0xe4/0x1f8) [<0000014b75e7b758>] apmask_store+0x68/0x140 [<0000014b75679196>] kernfs_fop_write_iter+0x14e/0x1e8 [<0000014b75598524>] vfs_write+0x1b4/0x448 [<0000014b7559894c>] ksys_write+0x74/0x100 [<0000014b7618a440>] __do_syscall+0x268/0x328 [<0000014b761a3558>] system_call+0x70/0x98 INFO: lockdep is turned off. Last Breaking-Event-Address: [<0000014b75e7b636>] ap_parse_bitmap_str+0x13e/0x1f8 Kernel panic - not syncing: Fatal exception: panic_on_oops occured when /sys/bus/ap/a[pq]mask was updated with a relative mask value (like +0x10-0x12,+60,-90) with one of the numeric values exceeding INT_MAX. The fix is simple: use unsigned long values for the internal variables. The correct checks are already in place in the function but a simple int for the internal variables was used with the possibility to overflow.

In the Linux kernel, the following vulnerability has been resolved: genirq/irqdesc: Prevent use-after-free in irq_find_at_or_after() irq_find_at_or_after() dereferences the interrupt descriptor which is returned by mt_find() while neither holding sparse_irq_lock nor RCU read lock, which means the descriptor can be freed between mt_find() and the dereference: CPU0 CPU1 desc = mt_find() delayed_free_desc(desc) irq_desc_get_irq(desc) The use-after-free is reported by KASAN: Call trace: irq_get_next_irq+0x58/0x84 show_stat+0x638/0x824 seq_read_iter+0x158/0x4ec proc_reg_read_iter+0x94/0x12c vfs_read+0x1e0/0x2c8 Freed by task 4471: slab_free_freelist_hook+0x174/0x1e0 __kmem_cache_free+0xa4/0x1dc kfree+0x64/0x128 irq_kobj_release+0x28/0x3c kobject_put+0xcc/0x1e0 delayed_free_desc+0x14/0x2c rcu_do_batch+0x214/0x720 Guard the access with a RCU read lock section.

In the Linux kernel, the following vulnerability has been resolved: media: lgdt3306a: Add a check against null-pointer-def The driver should check whether the client provides the platform_data. The following log reveals it: [ 29.610324] BUG: KASAN: null-ptr-deref in kmemdup+0x30/0x40 [ 29.610730] Read of size 40 at addr 0000000000000000 by task bash/414 [ 29.612820] Call Trace: [ 29.613030] <TASK> [ 29.613201] dump_stack_lvl+0x56/0x6f [ 29.613496] ? kmemdup+0x30/0x40 [ 29.613754] print_report.cold+0x494/0x6b7 [ 29.614082] ? kmemdup+0x30/0x40 [ 29.614340] kasan_report+0x8a/0x190 [ 29.614628] ? kmemdup+0x30/0x40 [ 29.614888] kasan_check_range+0x14d/0x1d0 [ 29.615213] memcpy+0x20/0x60 [ 29.615454] kmemdup+0x30/0x40 [ 29.615700] lgdt3306a_probe+0x52/0x310 [ 29.616339] i2c_device_probe+0x951/0xa90

In the Linux kernel, the following vulnerability has been resolved: blk-cgroup: fix list corruption from reorder of WRITE ->lqueued __blkcg_rstat_flush() can be run anytime, especially when blk_cgroup_bio_start is being executed. If WRITE of `->lqueued` is re-ordered with READ of 'bisc->lnode.next' in the loop of __blkcg_rstat_flush(), `next_bisc` can be assigned with one stat instance being added in blk_cgroup_bio_start(), then the local list in __blkcg_rstat_flush() could be corrupted. Fix the issue by adding one barrier.

In the Linux kernel, the following vulnerability has been resolved: fpga: manager: add owner module and take its refcount The current implementation of the fpga manager assumes that the low-level module registers a driver for the parent device and uses its owner pointer to take the module's refcount. This approach is problematic since it can lead to a null pointer dereference while attempting to get the manager if the parent device does not have a driver. To address this problem, add a module owner pointer to the fpga_manager struct and use it to take the module's refcount. Modify the functions for registering the manager to take an additional owner module parameter and rename them to avoid conflicts. Use the old function names for helper macros that automatically set the module that registers the manager as the owner. This ensures compatibility with existing low-level control modules and reduces the chances of registering a manager without setting the owner. Also, update the documentation to keep it consistent with the new interface for registering an fpga manager. Other changes: opportunistically move put_device() from __fpga_mgr_get() to fpga_mgr_get() and of_fpga_mgr_get() to improve code clarity since the manager device is taken in these functions.

In the Linux kernel, the following vulnerability has been resolved: fpga: bridge: add owner module and take its refcount The current implementation of the fpga bridge assumes that the low-level module registers a driver for the parent device and uses its owner pointer to take the module's refcount. This approach is problematic since it can lead to a null pointer dereference while attempting to get the bridge if the parent device does not have a driver. To address this problem, add a module owner pointer to the fpga_bridge struct and use it to take the module's refcount. Modify the function for registering a bridge to take an additional owner module parameter and rename it to avoid conflicts. Use the old function name for a helper macro that automatically sets the module that registers the bridge as the owner. This ensures compatibility with existing low-level control modules and reduces the chances of registering a bridge without setting the owner. Also, update the documentation to keep it consistent with the new interface for registering an fpga bridge. Other changes: opportunistically move put_device() from __fpga_bridge_get() to fpga_bridge_get() and of_fpga_bridge_get() to improve code clarity since the bridge device is taken in these functions.

In the Linux kernel, the following vulnerability has been resolved: fpga: region: add owner module and take its refcount The current implementation of the fpga region assumes that the low-level module registers a driver for the parent device and uses its owner pointer to take the module's refcount. This approach is problematic since it can lead to a null pointer dereference while attempting to get the region during programming if the parent device does not have a driver. To address this problem, add a module owner pointer to the fpga_region struct and use it to take the module's refcount. Modify the functions for registering a region to take an additional owner module parameter and rename them to avoid conflicts. Use the old function names for helper macros that automatically set the module that registers the region as the owner. This ensures compatibility with existing low-level control modules and reduces the chances of registering a region without setting the owner. Also, update the documentation to keep it consistent with the new interface for registering an fpga region.

In the Linux kernel, the following vulnerability has been resolved: PCI: of_property: Return error for int_map allocation failure Return -ENOMEM from of_pci_prop_intr_map() if kcalloc() fails to prevent a NULL pointer dereference in this case. [bhelgaas: commit log]

In the Linux kernel, the following vulnerability has been resolved: f2fs: compress: fix to cover {reserve,release}_compress_blocks() w/ cp_rwsem lock It needs to cover {reserve,release}_compress_blocks() w/ cp_rwsem lock to avoid racing with checkpoint, otherwise, filesystem metadata including blkaddr in dnode, inode fields and .total_valid_block_count may be corrupted after SPO case.

In the Linux kernel, the following vulnerability has been resolved: SUNRPC: Fix loop termination condition in gss_free_in_token_pages() The in_token->pages[] array is not NULL terminated. This results in the following KASAN splat: KASAN: maybe wild-memory-access in range [0x04a2013400000008-0x04a201340000000f]

In the Linux kernel, the following vulnerability has been resolved: serial: max3100: Update uart_driver_registered on driver removal The removal of the last MAX3100 device triggers the removal of the driver. However, code doesn't update the respective global variable and after insmod — rmmod — insmod cycle the kernel oopses: max3100 spi-PRP0001:01: max3100_probe: adding port 0 BUG: kernel NULL pointer dereference, address: 0000000000000408 ... RIP: 0010:serial_core_register_port+0xa0/0x840 ... max3100_probe+0x1b6/0x280 [max3100] spi_probe+0x8d/0xb0 Update the actual state so next time UART driver will be registered again. Hugo also noticed, that the error path in the probe also affected by having the variable set, and not cleared. Instead of clearing it move the assignment after the successfull uart_register_driver() call.

In the Linux kernel, the following vulnerability has been resolved: watchdog: cpu5wdt.c: Fix use-after-free bug caused by cpu5wdt_trigger When the cpu5wdt module is removing, the origin code uses del_timer() to de-activate the timer. If the timer handler is running, del_timer() could not stop it and will return directly. If the port region is released by release_region() and then the timer handler cpu5wdt_trigger() calls outb() to write into the region that is released, the use-after-free bug will happen. Change del_timer() to timer_shutdown_sync() in order that the timer handler could be finished before the port region is released.

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: u_audio: Fix race condition use of controls after free during gadget unbind. Hang on to the control IDs instead of pointers since those are correctly handled with locks.

In the Linux kernel, the following vulnerability has been resolved: stm class: Fix a double free in stm_register_device() The put_device(&stm->dev) call will trigger stm_device_release() which frees "stm" so the vfree(stm) on the next line is a double free.

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: Check 'folio' pointer for NULL It can be NULL if bmap is called.

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: Use variable length array instead of fixed size Should fix smatch warning: ntfs_set_label() error: __builtin_memcpy() 'uni->name' too small (20 vs 256)

In the Linux kernel, the following vulnerability has been resolved: drm/msm/a6xx: Avoid a nullptr dereference when speedbin setting fails Calling a6xx_destroy() before adreno_gpu_init() leads to a null pointer dereference on: msm_gpu_cleanup() : platform_set_drvdata(gpu->pdev, NULL); as gpu->pdev is only assigned in: a6xx_gpu_init() |_ adreno_gpu_init |_ msm_gpu_init() Instead of relying on handwavy null checks down the cleanup chain, explicitly de-allocate the LLC data and free a6xx_gpu instead. Patchwork: https://patchwork.freedesktop.org/patch/588919/