CVE Database

In the Linux kernel, the following vulnerability has been resolved: ext4: avoid use-after-free in ext4_ext_show_leaf() In ext4_find_extent(), path may be freed by error or be reallocated, so using a previously saved *ppath may have been freed and thus may trigger use-after-free, as follows: ext4_split_extent path = *ppath; ext4_split_extent_at(ppath) path = ext4_find_extent(ppath) ext4_split_extent_at(ppath) // ext4_find_extent fails to free path // but zeroout succeeds ext4_ext_show_leaf(inode, path) eh = path[depth].p_hdr // path use-after-free !!! Similar to ext4_split_extent_at(), we use *ppath directly as an input to ext4_ext_show_leaf(). Fix a spelling error by the way. Same problem in ext4_ext_handle_unwritten_extents(). Since 'path' is only used in ext4_ext_show_leaf(), remove 'path' and use *ppath directly. This issue is triggered only when EXT_DEBUG is defined and therefore does not affect functionality.

In the Linux kernel, the following vulnerability has been resolved: ext4: fix slab-use-after-free in ext4_split_extent_at() We hit the following use-after-free: ================================================================== BUG: KASAN: slab-use-after-free in ext4_split_extent_at+0xba8/0xcc0 Read of size 2 at addr ffff88810548ed08 by task kworker/u20:0/40 CPU: 0 PID: 40 Comm: kworker/u20:0 Not tainted 6.9.0-dirty #724 Call Trace: <TASK> kasan_report+0x93/0xc0 ext4_split_extent_at+0xba8/0xcc0 ext4_split_extent.isra.0+0x18f/0x500 ext4_split_convert_extents+0x275/0x750 ext4_ext_handle_unwritten_extents+0x73e/0x1580 ext4_ext_map_blocks+0xe20/0x2dc0 ext4_map_blocks+0x724/0x1700 ext4_do_writepages+0x12d6/0x2a70 [...] Allocated by task 40: __kmalloc_noprof+0x1ac/0x480 ext4_find_extent+0xf3b/0x1e70 ext4_ext_map_blocks+0x188/0x2dc0 ext4_map_blocks+0x724/0x1700 ext4_do_writepages+0x12d6/0x2a70 [...] Freed by task 40: kfree+0xf1/0x2b0 ext4_find_extent+0xa71/0x1e70 ext4_ext_insert_extent+0xa22/0x3260 ext4_split_extent_at+0x3ef/0xcc0 ext4_split_extent.isra.0+0x18f/0x500 ext4_split_convert_extents+0x275/0x750 ext4_ext_handle_unwritten_extents+0x73e/0x1580 ext4_ext_map_blocks+0xe20/0x2dc0 ext4_map_blocks+0x724/0x1700 ext4_do_writepages+0x12d6/0x2a70 [...] ================================================================== The flow of issue triggering is as follows: ext4_split_extent_at path = *ppath ext4_ext_insert_extent(ppath) ext4_ext_create_new_leaf(ppath) ext4_find_extent(orig_path) path = *orig_path read_extent_tree_block // return -ENOMEM or -EIO ext4_free_ext_path(path) kfree(path) *orig_path = NULL a. If err is -ENOMEM: ext4_ext_dirty(path + path->p_depth) // path use-after-free !!! b. If err is -EIO and we have EXT_DEBUG defined: ext4_ext_show_leaf(path) eh = path[depth].p_hdr // path also use-after-free !!! So when trying to zeroout or fix the extent length, call ext4_find_extent() to update the path. In addition we use *ppath directly as an ext4_ext_show_leaf() input to avoid possible use-after-free when EXT_DEBUG is defined, and to avoid unnecessary path updates.

In the Linux kernel, the following vulnerability has been resolved: ext4: aovid use-after-free in ext4_ext_insert_extent() As Ojaswin mentioned in Link, in ext4_ext_insert_extent(), if the path is reallocated in ext4_ext_create_new_leaf(), we'll use the stale path and cause UAF. Below is a sample trace with dummy values: ext4_ext_insert_extent path = *ppath = 2000 ext4_ext_create_new_leaf(ppath) ext4_find_extent(ppath) path = *ppath = 2000 if (depth > path[0].p_maxdepth) kfree(path = 2000); *ppath = path = NULL; path = kcalloc() = 3000 *ppath = 3000; return path; /* here path is still 2000, UAF! */ eh = path[depth].p_hdr ================================================================== BUG: KASAN: slab-use-after-free in ext4_ext_insert_extent+0x26d4/0x3330 Read of size 8 at addr ffff8881027bf7d0 by task kworker/u36:1/179 CPU: 3 UID: 0 PID: 179 Comm: kworker/u6:1 Not tainted 6.11.0-rc2-dirty #866 Call Trace: <TASK> ext4_ext_insert_extent+0x26d4/0x3330 ext4_ext_map_blocks+0xe22/0x2d40 ext4_map_blocks+0x71e/0x1700 ext4_do_writepages+0x1290/0x2800 [...] Allocated by task 179: ext4_find_extent+0x81c/0x1f70 ext4_ext_map_blocks+0x146/0x2d40 ext4_map_blocks+0x71e/0x1700 ext4_do_writepages+0x1290/0x2800 ext4_writepages+0x26d/0x4e0 do_writepages+0x175/0x700 [...] Freed by task 179: kfree+0xcb/0x240 ext4_find_extent+0x7c0/0x1f70 ext4_ext_insert_extent+0xa26/0x3330 ext4_ext_map_blocks+0xe22/0x2d40 ext4_map_blocks+0x71e/0x1700 ext4_do_writepages+0x1290/0x2800 ext4_writepages+0x26d/0x4e0 do_writepages+0x175/0x700 [...] ================================================================== So use *ppath to update the path to avoid the above problem.

In the Linux kernel, the following vulnerability has been resolved: ext4: fix double brelse() the buffer of the extents path In ext4_ext_try_to_merge_up(), set path[1].p_bh to NULL after it has been released, otherwise it may be released twice. An example of what triggers this is as follows: split2 map split1 |--------|-------|--------| ext4_ext_map_blocks ext4_ext_handle_unwritten_extents ext4_split_convert_extents // path->p_depth == 0 ext4_split_extent // 1. do split1 ext4_split_extent_at |ext4_ext_insert_extent | ext4_ext_create_new_leaf | ext4_ext_grow_indepth | le16_add_cpu(&neh->eh_depth, 1) | ext4_find_extent | // return -ENOMEM |// get error and try zeroout |path = ext4_find_extent | path->p_depth = 1 |ext4_ext_try_to_merge | ext4_ext_try_to_merge_up | path->p_depth = 0 | brelse(path[1].p_bh) ---> not set to NULL here |// zeroout success // 2. update path ext4_find_extent // 3. do split2 ext4_split_extent_at ext4_ext_insert_extent ext4_ext_create_new_leaf ext4_ext_grow_indepth le16_add_cpu(&neh->eh_depth, 1) ext4_find_extent path[0].p_bh = NULL; path->p_depth = 1 read_extent_tree_block ---> return err // path[1].p_bh is still the old value ext4_free_ext_path ext4_ext_drop_refs // path->p_depth == 1 brelse(path[1].p_bh) ---> brelse a buffer twice Finally got the following WARRNING when removing the buffer from lru: ============================================ VFS: brelse: Trying to free free buffer WARNING: CPU: 2 PID: 72 at fs/buffer.c:1241 __brelse+0x58/0x90 CPU: 2 PID: 72 Comm: kworker/u19:1 Not tainted 6.9.0-dirty #716 RIP: 0010:__brelse+0x58/0x90 Call Trace: <TASK> __find_get_block+0x6e7/0x810 bdev_getblk+0x2b/0x480 __ext4_get_inode_loc+0x48a/0x1240 ext4_get_inode_loc+0xb2/0x150 ext4_reserve_inode_write+0xb7/0x230 __ext4_mark_inode_dirty+0x144/0x6a0 ext4_ext_insert_extent+0x9c8/0x3230 ext4_ext_map_blocks+0xf45/0x2dc0 ext4_map_blocks+0x724/0x1700 ext4_do_writepages+0x12d6/0x2a70 [...] ============================================

In the Linux kernel, the following vulnerability has been resolved: ext4: fix off by one issue in alloc_flex_gd() Wesley reported an issue: ================================================================== EXT4-fs (dm-5): resizing filesystem from 7168 to 786432 blocks ------------[ cut here ]------------ kernel BUG at fs/ext4/resize.c:324! CPU: 9 UID: 0 PID: 3576 Comm: resize2fs Not tainted 6.11.0+ #27 RIP: 0010:ext4_resize_fs+0x1212/0x12d0 Call Trace: __ext4_ioctl+0x4e0/0x1800 ext4_ioctl+0x12/0x20 __x64_sys_ioctl+0x99/0xd0 x64_sys_call+0x1206/0x20d0 do_syscall_64+0x72/0x110 entry_SYSCALL_64_after_hwframe+0x76/0x7e ================================================================== While reviewing the patch, Honza found that when adjusting resize_bg in alloc_flex_gd(), it was possible for flex_gd->resize_bg to be bigger than flexbg_size. The reproduction of the problem requires the following: o_group = flexbg_size * 2 * n; o_size = (o_group + 1) * group_size; n_group: [o_group + flexbg_size, o_group + flexbg_size * 2) o_size = (n_group + 1) * group_size; Take n=0,flexbg_size=16 as an example: last:15 |o---------------|--------------n-| o_group:0 resize to n_group:30 The corresponding reproducer is: img=test.img rm -f $img truncate -s 600M $img mkfs.ext4 -F $img -b 1024 -G 16 8M dev=`losetup -f --show $img` mkdir -p /tmp/test mount $dev /tmp/test resize2fs $dev 248M Delete the problematic plus 1 to fix the issue, and add a WARN_ON_ONCE() to prevent the issue from happening again. [ Note: another reproucer which this commit fixes is: img=test.img rm -f $img truncate -s 25MiB $img mkfs.ext4 -b 4096 -E nodiscard,lazy_itable_init=0,lazy_journal_init=0 $img truncate -s 3GiB $img dev=`losetup -f --show $img` mkdir -p /tmp/test mount $dev /tmp/test resize2fs $dev 3G umount $dev losetup -d $dev -- TYT ]

In the Linux kernel, the following vulnerability has been resolved: drm/xe: fix UAF around queue destruction We currently do stuff like queuing the final destruction step on a random system wq, which will outlive the driver instance. With bad timing we can teardown the driver with one or more work workqueue still being alive leading to various UAF splats. Add a fini step to ensure user queues are properly torn down. At this point GuC should already be nuked so queue itself should no longer be referenced from hw pov. v2 (Matt B) - Looks much safer to use a waitqueue and then just wait for the xa_array to become empty before triggering the drain. (cherry picked from commit 861108666cc0e999cffeab6aff17b662e68774e3)

In the Linux kernel, the following vulnerability has been resolved: i3c: master: svc: Fix use after free vulnerability in svc_i3c_master Driver Due to Race Condition In the svc_i3c_master_probe function, &master->hj_work is bound with svc_i3c_master_hj_work, &master->ibi_work is bound with svc_i3c_master_ibi_work. And svc_i3c_master_ibi_work can start the hj_work, svc_i3c_master_irq_handler can start the ibi_work. If we remove the module which will call svc_i3c_master_remove to make cleanup, it will free master->base through i3c_master_unregister while the work mentioned above will be used. The sequence of operations that may lead to a UAF bug is as follows: CPU0 CPU1 | svc_i3c_master_hj_work svc_i3c_master_remove | i3c_master_unregister(&master->base)| device_unregister(&master->dev) | device_release | //free master->base | | i3c_master_do_daa(&master->base) | //use master->base Fix it by ensuring that the work is canceled before proceeding with the cleanup in svc_i3c_master_remove.

In the Linux kernel, the following vulnerability has been resolved: btrfs: send: fix buffer overflow detection when copying path to cache entry Starting with commit c0247d289e73 ("btrfs: send: annotate struct name_cache_entry with __counted_by()") we annotated the variable length array "name" from the name_cache_entry structure with __counted_by() to improve overflow detection. However that alone was not correct, because the length of that array does not match the "name_len" field - it matches that plus 1 to include the NUL string terminator, so that makes a fortified kernel think there's an overflow and report a splat like this: strcpy: detected buffer overflow: 20 byte write of buffer size 19 WARNING: CPU: 3 PID: 3310 at __fortify_report+0x45/0x50 CPU: 3 UID: 0 PID: 3310 Comm: btrfs Not tainted 6.11.0-prnet #1 Hardware name: CompuLab Ltd. sbc-ihsw/Intense-PC2 (IPC2), BIOS IPC2_3.330.7 X64 03/15/2018 RIP: 0010:__fortify_report+0x45/0x50 Code: 48 8b 34 (...) RSP: 0018:ffff97ebc0d6f650 EFLAGS: 00010246 RAX: 7749924ef60fa600 RBX: ffff8bf5446a521a RCX: 0000000000000027 RDX: 00000000ffffdfff RSI: ffff97ebc0d6f548 RDI: ffff8bf84e7a1cc8 RBP: ffff8bf548574080 R08: ffffffffa8c40e10 R09: 0000000000005ffd R10: 0000000000000004 R11: ffffffffa8c70e10 R12: ffff8bf551eef400 R13: 0000000000000000 R14: 0000000000000013 R15: 00000000000003a8 FS: 00007fae144de8c0(0000) GS:ffff8bf84e780000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fae14691690 CR3: 00000001027a2003 CR4: 00000000001706f0 Call Trace: <TASK> ? __warn+0x12a/0x1d0 ? __fortify_report+0x45/0x50 ? report_bug+0x154/0x1c0 ? handle_bug+0x42/0x70 ? exc_invalid_op+0x1a/0x50 ? asm_exc_invalid_op+0x1a/0x20 ? __fortify_report+0x45/0x50 __fortify_panic+0x9/0x10 __get_cur_name_and_parent+0x3bc/0x3c0 get_cur_path+0x207/0x3b0 send_extent_data+0x709/0x10d0 ? find_parent_nodes+0x22df/0x25d0 ? mas_nomem+0x13/0x90 ? mtree_insert_range+0xa5/0x110 ? btrfs_lru_cache_store+0x5f/0x1e0 ? iterate_extent_inodes+0x52d/0x5a0 process_extent+0xa96/0x11a0 ? __pfx_lookup_backref_cache+0x10/0x10 ? __pfx_store_backref_cache+0x10/0x10 ? __pfx_iterate_backrefs+0x10/0x10 ? __pfx_check_extent_item+0x10/0x10 changed_cb+0x6fa/0x930 ? tree_advance+0x362/0x390 ? memcmp_extent_buffer+0xd7/0x160 send_subvol+0xf0a/0x1520 btrfs_ioctl_send+0x106b/0x11d0 ? __pfx___clone_root_cmp_sort+0x10/0x10 _btrfs_ioctl_send+0x1ac/0x240 btrfs_ioctl+0x75b/0x850 __se_sys_ioctl+0xca/0x150 do_syscall_64+0x85/0x160 ? __count_memcg_events+0x69/0x100 ? handle_mm_fault+0x1327/0x15c0 ? __se_sys_rt_sigprocmask+0xf1/0x180 ? syscall_exit_to_user_mode+0x75/0xa0 ? do_syscall_64+0x91/0x160 ? do_user_addr_fault+0x21d/0x630 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fae145eeb4f Code: 00 48 89 (...) RSP: 002b:00007ffdf1cb09b0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fae145eeb4f RDX: 00007ffdf1cb0ad0 RSI: 0000000040489426 RDI: 0000000000000004 RBP: 00000000000078fe R08: 00007fae144006c0 R09: 00007ffdf1cb0927 R10: 0000000000000008 R11: 0000000000000246 R12: 00007ffdf1cb1ce8 R13: 0000000000000003 R14: 000055c499fab2e0 R15: 0000000000000004 </TASK> Fix this by not storing the NUL string terminator since we don't actually need it for name cache entries, this way "name_len" corresponds to the actual size of the "name" array. This requires marking the "name" array field with __nonstring and using memcpy() instead of strcpy() as recommended by the guidelines at: https://github.com/KSPP/linux/issues/90

In the Linux kernel, the following vulnerability has been resolved: drm/xe/vm: move xa_alloc to prevent UAF Evil user can guess the next id of the vm before the ioctl completes and then call vm destroy ioctl to trigger UAF since create ioctl is still referencing the same vm. Move the xa_alloc all the way to the end to prevent this. v2: - Rebase (cherry picked from commit dcfd3971327f3ee92765154baebbaece833d3ca9)

Nginx UI is a web user interface for the Nginx web server. Prior to version 2.0.0-beta.36, the log path of nginxui is controllable. This issue can be combined with the directory traversal at `/api/configs` to read directories and file contents on the server. Version 2.0.0-beta.36 fixes the issue.

Nginx UI is a web user interface for the Nginx web server. Nginx UI v2.0.0-beta.35 and earlier gets the value from the json field without verification, and can construct a value value in the form of `../../`. Arbitrary files can be written to the server, which may result in loss of permissions. Version 2.0.0-beta.26 fixes the issue.

A use-after-free vulnerability was found in the QEMU LSI53C895A SCSI Host Bus Adapter emulation. This issue can lead to a crash or VM escape.

OneDev is a Git server with CI/CD, kanban, and packages. A vulnerability in versions prior to 11.0.9 allows unauthenticated users to read arbitrary files accessible by the OneDev server process. This issue has been fixed in version 11.0.9.

In the Linux kernel, the following vulnerability has been resolved: powercap: intel_rapl: Fix off by one in get_rpi() The rp->priv->rpi array is either rpi_msr or rpi_tpmi which have NR_RAPL_PRIMITIVES number of elements. Thus the > needs to be >= to prevent an off by one access.

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix helper writes to read-only maps Lonial found an issue that despite user- and BPF-side frozen BPF map (like in case of .rodata), it was still possible to write into it from a BPF program side through specific helpers having ARG_PTR_TO_{LONG,INT} as arguments. In check_func_arg() when the argument is as mentioned, the meta->raw_mode is never set. Later, check_helper_mem_access(), under the case of PTR_TO_MAP_VALUE as register base type, it assumes BPF_READ for the subsequent call to check_map_access_type() and given the BPF map is read-only it succeeds. The helpers really need to be annotated as ARG_PTR_TO_{LONG,INT} | MEM_UNINIT when results are written into them as opposed to read out of them. The latter indicates that it's okay to pass a pointer to uninitialized memory as the memory is written to anyway. However, ARG_PTR_TO_{LONG,INT} is a special case of ARG_PTR_TO_FIXED_SIZE_MEM just with additional alignment requirement. So it is better to just get rid of the ARG_PTR_TO_{LONG,INT} special cases altogether and reuse the fixed size memory types. For this, add MEM_ALIGNED to additionally ensure alignment given these helpers write directly into the args via *<ptr> = val. The .arg*_size has been initialized reflecting the actual sizeof(*<ptr>). MEM_ALIGNED can only be used in combination with MEM_FIXED_SIZE annotated argument types, since in !MEM_FIXED_SIZE cases the verifier does not know the buffer size a priori and therefore cannot blindly write *<ptr> = val.

In the Linux kernel, the following vulnerability has been resolved: ACPI: sysfs: validate return type of _STR method Only buffer objects are valid return values of _STR. If something else is returned description_show() will access invalid memory.

In the Linux kernel, the following vulnerability has been resolved: nbd: fix race between timeout and normal completion If request timetout is handled by nbd_requeue_cmd(), normal completion has to be stopped for avoiding to complete this requeued request, other use-after-free can be triggered. Fix the race by clearing NBD_CMD_INFLIGHT in nbd_requeue_cmd(), meantime make sure that cmd->lock is grabbed for clearing the flag and the requeue.

In the Linux kernel, the following vulnerability has been resolved: block, bfq: fix uaf for accessing waker_bfqq after splitting After commit 42c306ed7233 ("block, bfq: don't break merge chain in bfq_split_bfqq()"), if the current procress is the last holder of bfqq, the bfqq can be freed after bfq_split_bfqq(). Hence recored the bfqq and then access bfqq->waker_bfqq may trigger UAF. What's more, the waker_bfqq may in the merge chain of bfqq, hence just recored waker_bfqq is still not safe. Fix the problem by adding a helper bfq_waker_bfqq() to check if bfqq->waker_bfqq is in the merge chain, and current procress is the only holder.

In the Linux kernel, the following vulnerability has been resolved: firmware: arm_scmi: Fix double free in OPTEE transport Channels can be shared between protocols, avoid freeing the same channel descriptors twice when unloading the stack.

In the Linux kernel, the following vulnerability has been resolved: scsi: elx: libefc: Fix potential use after free in efc_nport_vport_del() The kref_put() function will call nport->release if the refcount drops to zero. The nport->release release function is _efc_nport_free() which frees "nport". But then we dereference "nport" on the next line which is a use after free. Re-order these lines to avoid the use after free.

In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix potential oob read in nilfs_btree_check_delete() The function nilfs_btree_check_delete(), which checks whether degeneration to direct mapping occurs before deleting a b-tree entry, causes memory access outside the block buffer when retrieving the maximum key if the root node has no entries. This does not usually happen because b-tree mappings with 0 child nodes are never created by mkfs.nilfs2 or nilfs2 itself. However, it can happen if the b-tree root node read from a device is configured that way, so fix this potential issue by adding a check for that case.

In the Linux kernel, the following vulnerability has been resolved: PCI: kirin: Fix buffer overflow in kirin_pcie_parse_port() Within kirin_pcie_parse_port(), the pcie->num_slots is compared to pcie->gpio_id_reset size (MAX_PCI_SLOTS) which is correct and would lead to an overflow. Thus, fix condition to pcie->num_slots + 1 >= MAX_PCI_SLOTS and move pcie->num_slots increment below the if-statement to avoid out-of-bounds array access. Found by Linux Verification Center (linuxtesting.org) with SVACE. [kwilczynski: commit log]

In the Linux kernel, the following vulnerability has been resolved: RDMA/hns: Fix Use-After-Free of rsv_qp on HIP08 Currently rsv_qp is freed before ib_unregister_device() is called on HIP08. During the time interval, users can still dereg MR and rsv_qp will be used in this process, leading to a UAF. Move the release of rsv_qp after calling ib_unregister_device() to fix it.

In the Linux kernel, the following vulnerability has been resolved: vhost_vdpa: assign irq bypass producer token correctly We used to call irq_bypass_unregister_producer() in vhost_vdpa_setup_vq_irq() which is problematic as we don't know if the token pointer is still valid or not. Actually, we use the eventfd_ctx as the token so the life cycle of the token should be bound to the VHOST_SET_VRING_CALL instead of vhost_vdpa_setup_vq_irq() which could be called by set_status(). Fixing this by setting up irq bypass producer's token when handling VHOST_SET_VRING_CALL and un-registering the producer before calling vhost_vring_ioctl() to prevent a possible use after free as eventfd could have been released in vhost_vring_ioctl(). And such registering and unregistering will only be done if DRIVER_OK is set.

In the Linux kernel, the following vulnerability has been resolved: net: seeq: Fix use after free vulnerability in ether3 Driver Due to Race Condition In the ether3_probe function, a timer is initialized with a callback function ether3_ledoff, bound to &prev(dev)->timer. Once the timer is started, there is a risk of a race condition if the module or device is removed, triggering the ether3_remove function to perform cleanup. The sequence of operations that may lead to a UAF bug is as follows: CPU0 CPU1 | ether3_ledoff ether3_remove | free_netdev(dev); | put_devic | kfree(dev); | | ether3_outw(priv(dev)->regs.config2 |= CFG2_CTRLO, REG_CONFIG2); | // use dev Fix it by ensuring that the timer is canceled before proceeding with the cleanup in ether3_remove.

In the Linux kernel, the following vulnerability has been resolved: mm: call the security_mmap_file() LSM hook in remap_file_pages() The remap_file_pages syscall handler calls do_mmap() directly, which doesn't contain the LSM security check. And if the process has called personality(READ_IMPLIES_EXEC) before and remap_file_pages() is called for RW pages, this will actually result in remapping the pages to RWX, bypassing a W^X policy enforced by SELinux. So we should check prot by security_mmap_file LSM hook in the remap_file_pages syscall handler before do_mmap() is called. Otherwise, it potentially permits an attacker to bypass a W^X policy enforced by SELinux. The bypass is similar to CVE-2016-10044, which bypass the same thing via AIO and can be found in [1]. The PoC: $ cat > test.c int main(void) { size_t pagesz = sysconf(_SC_PAGE_SIZE); int mfd = syscall(SYS_memfd_create, "test", 0); const char *buf = mmap(NULL, 4 * pagesz, PROT_READ | PROT_WRITE, MAP_SHARED, mfd, 0); unsigned int old = syscall(SYS_personality, 0xffffffff); syscall(SYS_personality, READ_IMPLIES_EXEC | old); syscall(SYS_remap_file_pages, buf, pagesz, 0, 2, 0); syscall(SYS_personality, old); // show the RWX page exists even if W^X policy is enforced int fd = open("/proc/self/maps", O_RDONLY); unsigned char buf2[1024]; while (1) { int ret = read(fd, buf2, 1024); if (ret <= 0) break; write(1, buf2, ret); } close(fd); } $ gcc test.c -o test $ ./test | grep rwx 7f1836c34000-7f1836c35000 rwxs 00002000 00:01 2050 /memfd:test (deleted) [PM: subject line tweaks]

In the Linux kernel, the following vulnerability has been resolved: firmware_loader: Block path traversal Most firmware names are hardcoded strings, or are constructed from fairly constrained format strings where the dynamic parts are just some hex numbers or such. However, there are a couple codepaths in the kernel where firmware file names contain string components that are passed through from a device or semi-privileged userspace; the ones I could find (not counting interfaces that require root privileges) are: - lpfc_sli4_request_firmware_update() seems to construct the firmware filename from "ModelName", a string that was previously parsed out of some descriptor ("Vital Product Data") in lpfc_fill_vpd() - nfp_net_fw_find() seems to construct a firmware filename from a model name coming from nfp_hwinfo_lookup(pf->hwinfo, "nffw.partno"), which I think parses some descriptor that was read from the device. (But this case likely isn't exploitable because the format string looks like "netronome/nic_%s", and there shouldn't be any *folders* starting with "netronome/nic_". The previous case was different because there, the "%s" is *at the start* of the format string.) - module_flash_fw_schedule() is reachable from the ETHTOOL_MSG_MODULE_FW_FLASH_ACT netlink command, which is marked as GENL_UNS_ADMIN_PERM (meaning CAP_NET_ADMIN inside a user namespace is enough to pass the privilege check), and takes a userspace-provided firmware name. (But I think to reach this case, you need to have CAP_NET_ADMIN over a network namespace that a special kind of ethernet device is mapped into, so I think this is not a viable attack path in practice.) Fix it by rejecting any firmware names containing ".." path components. For what it's worth, I went looking and haven't found any USB device drivers that use the firmware loader dangerously.

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix race setting file private on concurrent lseek using same fd When doing concurrent lseek(2) system calls against the same file descriptor, using multiple threads belonging to the same process, we have a short time window where a race happens and can result in a memory leak. The race happens like this: 1) A program opens a file descriptor for a file and then spawns two threads (with the pthreads library for example), lets call them task A and task B; 2) Task A calls lseek with SEEK_DATA or SEEK_HOLE and ends up at file.c:find_desired_extent() while holding a read lock on the inode; 3) At the start of find_desired_extent(), it extracts the file's private_data pointer into a local variable named 'private', which has a value of NULL; 4) Task B also calls lseek with SEEK_DATA or SEEK_HOLE, locks the inode in shared mode and enters file.c:find_desired_extent(), where it also extracts file->private_data into its local variable 'private', which has a NULL value; 5) Because it saw a NULL file private, task A allocates a private structure and assigns to the file structure; 6) Task B also saw a NULL file private so it also allocates its own file private and then assigns it to the same file structure, since both tasks are using the same file descriptor. At this point we leak the private structure allocated by task A. Besides the memory leak, there's also the detail that both tasks end up using the same cached state record in the private structure (struct btrfs_file_private::llseek_cached_state), which can result in a use-after-free problem since one task can free it while the other is still using it (only one task took a reference count on it). Also, sharing the cached state is not a good idea since it could result in incorrect results in the future - right now it should not be a problem because it end ups being used only in extent-io-tree.c:count_range_bits() where we do range validation before using the cached state. Fix this by protecting the private assignment and check of a file while holding the inode's spinlock and keep track of the task that allocated the private, so that it's used only by that task in order to prevent user-after-free issues with the cached state record as well as potentially using it incorrectly in the future.

In the Linux kernel, the following vulnerability has been resolved: crypto: hisilicon/qm - inject error before stopping queue The master ooo cannot be completely closed when the accelerator core reports memory error. Therefore, the driver needs to inject the qm error to close the master ooo. Currently, the qm error is injected after stopping queue, memory may be released immediately after stopping queue, causing the device to access the released memory. Therefore, error is injected to close master ooo before stopping queue to ensure that the device does not access the released memory.

In the Linux kernel, the following vulnerability has been resolved: x86/tdx: Fix "in-kernel MMIO" check TDX only supports kernel-initiated MMIO operations. The handle_mmio() function checks if the #VE exception occurred in the kernel and rejects the operation if it did not. However, userspace can deceive the kernel into performing MMIO on its behalf. For example, if userspace can point a syscall to an MMIO address, syscall does get_user() or put_user() on it, triggering MMIO #VE. The kernel will treat the #VE as in-kernel MMIO. Ensure that the target MMIO address is within the kernel before decoding instruction.