Search Results (20087 CVEs found)

CVE Vendors Products Updated CVSS v3.1
CVE-2025-68266 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: bfs: Reconstruct file type when loading from disk syzbot is reporting that S_IFMT bits of inode->i_mode can become bogus when the S_IFMT bits of the 32bits "mode" field loaded from disk are corrupted or when the 32bits "attributes" field loaded from disk are corrupted. A documentation says that BFS uses only lower 9 bits of the "mode" field. But I can't find an explicit explanation that the unused upper 23 bits (especially, the S_IFMT bits) are initialized with 0. Therefore, ignore the S_IFMT bits of the "mode" field loaded from disk. Also, verify that the value of the "attributes" field loaded from disk is either BFS_VREG or BFS_VDIR (because BFS supports only regular files and the root directory).
CVE-2025-68325 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: net/sched: sch_cake: Fix incorrect qlen reduction in cake_drop In cake_drop(), qdisc_tree_reduce_backlog() is used to update the qlen and backlog of the qdisc hierarchy. Its caller, cake_enqueue(), assumes that the parent qdisc will enqueue the current packet. However, this assumption breaks when cake_enqueue() returns NET_XMIT_CN: the parent qdisc stops enqueuing current packet, leaving the tree qlen/backlog accounting inconsistent. This mismatch can lead to a NULL dereference (e.g., when the parent Qdisc is qfq_qdisc). This patch computes the qlen/backlog delta in a more robust way by observing the difference before and after the series of cake_drop() calls, and then compensates the qdisc tree accounting if cake_enqueue() returns NET_XMIT_CN. To ensure correct compensation when ACK thinning is enabled, a new variable is introduced to keep qlen unchanged.
CVE-2025-68332 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: comedi: c6xdigio: Fix invalid PNP driver unregistration The Comedi low-level driver "c6xdigio" seems to be for a parallel port connected device. When the Comedi core calls the driver's Comedi "attach" handler `c6xdigio_attach()` to configure a Comedi to use this driver, it tries to enable the parallel port PNP resources by registering a PNP driver with `pnp_register_driver()`, but ignores the return value. (The `struct pnp_driver` it uses has only the `name` and `id_table` members filled in.) The driver's Comedi "detach" handler `c6xdigio_detach()` unconditionally unregisters the PNP driver with `pnp_unregister_driver()`. It is possible for `c6xdigio_attach()` to return an error before it calls `pnp_register_driver()` and it is possible for the call to `pnp_register_driver()` to return an error (that is ignored). In both cases, the driver should not be calling `pnp_unregister_driver()` as it does in `c6xdigio_detach()`. (Note that `c6xdigio_detach()` will be called by the Comedi core if `c6xdigio_attach()` returns an error, or if the Comedi core decides to detach the Comedi device from the driver for some other reason.) The unconditional call to `pnp_unregister_driver()` without a previous successful call to `pnp_register_driver()` will cause `driver_unregister()` to issue a warning "Unexpected driver unregister!". This was detected by Syzbot [1]. Also, the PNP driver registration and unregistration should be done at module init and exit time, respectively, not when attaching or detaching Comedi devices to the driver. (There might be more than one Comedi device being attached to the driver, although that is unlikely.) Change the driver to do the PNP driver registration at module init time, and the unregistration at module exit time. Since `c6xdigio_detach()` now only calls `comedi_legacy_detach()`, remove the function and change the Comedi driver "detach" handler to `comedi_legacy_detach`. ------------------------------------------- [1] Syzbot sample crash report: Unexpected driver unregister! WARNING: CPU: 0 PID: 5970 at drivers/base/driver.c:273 driver_unregister drivers/base/driver.c:273 [inline] WARNING: CPU: 0 PID: 5970 at drivers/base/driver.c:273 driver_unregister+0x90/0xb0 drivers/base/driver.c:270 Modules linked in: CPU: 0 UID: 0 PID: 5970 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:driver_unregister drivers/base/driver.c:273 [inline] RIP: 0010:driver_unregister+0x90/0xb0 drivers/base/driver.c:270 Code: 48 89 ef e8 c2 e6 82 fc 48 89 df e8 3a 93 ff ff 5b 5d e9 c3 6d d9 fb e8 be 6d d9 fb 90 48 c7 c7 e0 f8 1f 8c e8 51 a2 97 fb 90 <0f> 0b 90 90 5b 5d e9 a5 6d d9 fb e8 e0 f4 41 fc eb 94 e8 d9 f4 41 RSP: 0018:ffffc9000373f9a0 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffffffff8ff24720 RCX: ffffffff817b6ee8 RDX: ffff88807c932480 RSI: ffffffff817b6ef5 RDI: 0000000000000001 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffffffff8ff24660 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff88814cca0000 FS: 000055556dab1500(0000) GS:ffff8881249d9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055f77f285cd0 CR3: 000000007d871000 CR4: 00000000003526f0 Call Trace: <TASK> comedi_device_detach_locked+0x12f/0xa50 drivers/comedi/drivers.c:207 comedi_device_detach+0x67/0xb0 drivers/comedi/drivers.c:215 comedi_device_attach+0x43d/0x900 drivers/comedi/drivers.c:1011 do_devconfig_ioctl+0x1b1/0x710 drivers/comedi/comedi_fops.c:872 comedi_unlocked_ioctl+0x165d/0x2f00 drivers/comedi/comedi_fops.c:2178 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_sys ---truncated---
CVE-2025-68335 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: comedi: pcl818: fix null-ptr-deref in pcl818_ai_cancel() Syzbot identified an issue [1] in pcl818_ai_cancel(), which stems from the fact that in case of early device detach via pcl818_detach(), subdevice dev->read_subdev may not have initialized its pointer to &struct comedi_async as intended. Thus, any such dereferencing of &s->async->cmd will lead to general protection fault and kernel crash. Mitigate this problem by removing a call to pcl818_ai_cancel() from pcl818_detach() altogether. This way, if the subdevice setups its support for async commands, everything async-related will be handled via subdevice's own ->cancel() function in comedi_device_detach_locked() even before pcl818_detach(). If no support for asynchronous commands is provided, there is no need to cancel anything either. [1] Syzbot crash: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f] CPU: 1 UID: 0 PID: 6050 Comm: syz.0.18 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:pcl818_ai_cancel+0x69/0x3f0 drivers/comedi/drivers/pcl818.c:762 ... Call Trace: <TASK> pcl818_detach+0x66/0xd0 drivers/comedi/drivers/pcl818.c:1115 comedi_device_detach_locked+0x178/0x750 drivers/comedi/drivers.c:207 do_devconfig_ioctl drivers/comedi/comedi_fops.c:848 [inline] comedi_unlocked_ioctl+0xcde/0x1020 drivers/comedi/comedi_fops.c:2178 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] ...
CVE-2025-68345 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: ALSA: hda: cs35l41: Fix NULL pointer dereference in cs35l41_hda_read_acpi() The acpi_get_first_physical_node() function can return NULL, in which case the get_device() function also returns NULL, but this value is then dereferenced without checking,so add a check to prevent a crash. Found by Linux Verification Center (linuxtesting.org) with SVACE.
CVE-2025-68346 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: ALSA: dice: fix buffer overflow in detect_stream_formats() The function detect_stream_formats() reads the stream_count value directly from a FireWire device without validating it. This can lead to out-of-bounds writes when a malicious device provides a stream_count value greater than MAX_STREAMS. Fix by applying the same validation to both TX and RX stream counts in detect_stream_formats().
CVE-2025-68347 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: ALSA: firewire-motu: fix buffer overflow in hwdep read for DSP events The DSP event handling code in hwdep_read() could write more bytes to the user buffer than requested, when a user provides a buffer smaller than the event header size (8 bytes). Fix by using min_t() to clamp the copy size, This ensures we never copy more than the user requested.
CVE-2025-68354 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: regulator: core: Protect regulator_supply_alias_list with regulator_list_mutex regulator_supply_alias_list was accessed without any locking in regulator_supply_alias(), regulator_register_supply_alias(), and regulator_unregister_supply_alias(). Concurrent registration, unregistration and lookups can race, leading to: 1 use-after-free if an alias entry is removed while being read, 2 duplicate entries when two threads register the same alias, 3 inconsistent alias mappings observed by consumers. Protect all traversals, insertions and deletions on regulator_supply_alias_list with the existing regulator_list_mutex.
CVE-2025-68362 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: wifi: rtl818x: rtl8187: Fix potential buffer underflow in rtl8187_rx_cb() The rtl8187_rx_cb() calculates the rx descriptor header address by subtracting its size from the skb tail pointer. However, it does not validate if the received packet (skb->len from urb->actual_length) is large enough to contain this header. If a truncated packet is received, this will lead to a buffer underflow, reading memory before the start of the skb data area, and causing a kernel panic. Add length checks for both rtl8187 and rtl8187b descriptor headers before attempting to access them, dropping the packet cleanly if the check fails.
CVE-2025-68363 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: bpf: Check skb->transport_header is set in bpf_skb_check_mtu The bpf_skb_check_mtu helper needs to use skb->transport_header when the BPF_MTU_CHK_SEGS flag is used: bpf_skb_check_mtu(skb, ifindex, &mtu_len, 0, BPF_MTU_CHK_SEGS) The transport_header is not always set. There is a WARN_ON_ONCE report when CONFIG_DEBUG_NET is enabled + skb->gso_size is set + bpf_prog_test_run is used: WARNING: CPU: 1 PID: 2216 at ./include/linux/skbuff.h:3071 skb_gso_validate_network_len bpf_skb_check_mtu bpf_prog_3920e25740a41171_tc_chk_segs_flag # A test in the next patch bpf_test_run bpf_prog_test_run_skb For a normal ingress skb (not test_run), skb_reset_transport_header is performed but there is plan to avoid setting it as described in commit 2170a1f09148 ("net: no longer reset transport_header in __netif_receive_skb_core()"). This patch fixes the bpf helper by checking skb_transport_header_was_set(). The check is done just before skb->transport_header is used, to avoid breaking the existing bpf prog. The WARN_ON_ONCE is limited to bpf_prog_test_run, so targeting bpf-next.
CVE-2025-68369 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: ntfs3: init run lock for extend inode After setting the inode mode of $Extend to a regular file, executing the truncate system call will enter the do_truncate() routine, causing the run_lock uninitialized error reported by syzbot. Prior to patch 4e8011ffec79, if the inode mode of $Extend was not set to a regular file, the do_truncate() routine would not be entered. Add the run_lock initialization when loading $Extend. syzbot reported: INFO: trying to register non-static key. Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 assign_lock_key+0x133/0x150 kernel/locking/lockdep.c:984 register_lock_class+0x105/0x320 kernel/locking/lockdep.c:1299 __lock_acquire+0x99/0xd20 kernel/locking/lockdep.c:5112 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 down_write+0x96/0x1f0 kernel/locking/rwsem.c:1590 ntfs_set_size+0x140/0x200 fs/ntfs3/inode.c:860 ntfs_extend+0x1d9/0x970 fs/ntfs3/file.c:387 ntfs_setattr+0x2e8/0xbe0 fs/ntfs3/file.c:808
CVE-2025-68374 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: md: fix rcu protection in md_wakeup_thread We attempted to use RCU to protect the pointer 'thread', but directly passed the value when calling md_wakeup_thread(). This means that the RCU pointer has been acquired before rcu_read_lock(), which renders rcu_read_lock() ineffective and could lead to a use-after-free.
CVE-2025-68379 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: Fix null deref on srq->rq.queue after resize failure A NULL pointer dereference can occur in rxe_srq_chk_attr() when ibv_modify_srq() is invoked twice in succession under certain error conditions. The first call may fail in rxe_queue_resize(), which leads rxe_srq_from_attr() to set srq->rq.queue = NULL. The second call then triggers a crash (null deref) when accessing srq->rq.queue->buf->index_mask. Call Trace: <TASK> rxe_modify_srq+0x170/0x480 [rdma_rxe] ? __pfx_rxe_modify_srq+0x10/0x10 [rdma_rxe] ? uverbs_try_lock_object+0x4f/0xa0 [ib_uverbs] ? rdma_lookup_get_uobject+0x1f0/0x380 [ib_uverbs] ib_uverbs_modify_srq+0x204/0x290 [ib_uverbs] ? __pfx_ib_uverbs_modify_srq+0x10/0x10 [ib_uverbs] ? tryinc_node_nr_active+0xe6/0x150 ? uverbs_fill_udata+0xed/0x4f0 [ib_uverbs] ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0x2c0/0x470 [ib_uverbs] ? __pfx_ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0x10/0x10 [ib_uverbs] ? uverbs_fill_udata+0xed/0x4f0 [ib_uverbs] ib_uverbs_run_method+0x55a/0x6e0 [ib_uverbs] ? __pfx_ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0x10/0x10 [ib_uverbs] ib_uverbs_cmd_verbs+0x54d/0x800 [ib_uverbs] ? __pfx_ib_uverbs_cmd_verbs+0x10/0x10 [ib_uverbs] ? __pfx___raw_spin_lock_irqsave+0x10/0x10 ? __pfx_do_vfs_ioctl+0x10/0x10 ? ioctl_has_perm.constprop.0.isra.0+0x2c7/0x4c0 ? __pfx_ioctl_has_perm.constprop.0.isra.0+0x10/0x10 ib_uverbs_ioctl+0x13e/0x220 [ib_uverbs] ? __pfx_ib_uverbs_ioctl+0x10/0x10 [ib_uverbs] __x64_sys_ioctl+0x138/0x1c0 do_syscall_64+0x82/0x250 ? fdget_pos+0x58/0x4c0 ? ksys_write+0xf3/0x1c0 ? __pfx_ksys_write+0x10/0x10 ? do_syscall_64+0xc8/0x250 ? __pfx_vm_mmap_pgoff+0x10/0x10 ? fget+0x173/0x230 ? fput+0x2a/0x80 ? ksys_mmap_pgoff+0x224/0x4c0 ? do_syscall_64+0xc8/0x250 ? do_user_addr_fault+0x37b/0xfe0 ? clear_bhb_loop+0x50/0xa0 ? clear_bhb_loop+0x50/0xa0 ? clear_bhb_loop+0x50/0xa0 entry_SYSCALL_64_after_hwframe+0x76/0x7e
CVE-2025-68758 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: backlight: led-bl: Add devlink to supplier LEDs LED Backlight is a consumer of one or multiple LED class devices, but devlink is currently unable to create correct supplier-producer links when the supplier is a class device. It creates instead a link where the supplier is the parent of the expected device. One consequence is that removal order is not correctly enforced. Issues happen for example with the following sections in a device tree overlay: // An LED driver chip pca9632@62 { compatible = "nxp,pca9632"; reg = <0x62>; // ... addon_led_pwm: led-pwm@3 { reg = <3>; label = "addon:led:pwm"; }; }; backlight-addon { compatible = "led-backlight"; leds = <&addon_led_pwm>; brightness-levels = <255>; default-brightness-level = <255>; }; In this example, the devlink should be created between the backlight-addon (consumer) and the pca9632@62 (supplier). Instead it is created between the backlight-addon (consumer) and the parent of the pca9632@62, which is typically the I2C bus adapter. On removal of the above overlay, the LED driver can be removed before the backlight device, resulting in: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010 ... Call trace: led_put+0xe0/0x140 devm_led_release+0x6c/0x98 Another way to reproduce the bug without any device tree overlays is unbinding the LED class device (pca9632@62) before unbinding the consumer (backlight-addon): echo 11-0062 >/sys/bus/i2c/drivers/leds-pca963x/unbind echo ...backlight-dock >/sys/bus/platform/drivers/led-backlight/unbind Fix by adding a devlink between the consuming led-backlight device and the supplying LED device, as other drivers and subsystems do as well.
CVE-2025-68380 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: wifi: ath11k: fix peer HE MCS assignment In ath11k_wmi_send_peer_assoc_cmd(), peer's transmit MCS is sent to firmware as receive MCS while peer's receive MCS sent as transmit MCS, which goes against firmwire's definition. While connecting to a misbehaved AP that advertises 0xffff (meaning not supported) for 160 MHz transmit MCS map, firmware crashes due to 0xffff is assigned to he_mcs->rx_mcs_set field. Ext Tag: HE Capabilities [...] Supported HE-MCS and NSS Set [...] Rx and Tx MCS Maps 160 MHz [...] Tx HE-MCS Map 160 MHz: 0xffff Swap the assignment to fix this issue. As the HE rate control mask is meant to limit our own transmit MCS, it needs to go via he_mcs->rx_mcs_set field. With the aforementioned swapping done, change is needed as well to apply it to the peer's receive MCS. Tested-on: WCN6855 hw2.1 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.41 Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.4.1-00199-QCAHKSWPL_SILICONZ-1
CVE-2025-68727 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: ntfs3: Fix uninit buffer allocated by __getname() Fix uninit errors caused after buffer allocation given to 'de'; by initializing the buffer with zeroes. The fix was found by using KMSAN.
CVE-2025-68728 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: ntfs3: fix uninit memory after failed mi_read in mi_format_new Fix a KMSAN un-init bug found by syzkaller. ntfs_get_bh() expects a buffer from sb_getblk(), that buffer may not be uptodate. We do not bring the buffer uptodate before setting it as uptodate. If the buffer were to not be uptodate, it could mean adding a buffer with un-init data to the mi record. Attempting to load that record will trigger KMSAN. Avoid this by setting the buffer as uptodate, if it’s not already, by overwriting it.
CVE-2025-40025 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to do sanity check on node footer for non inode dnode As syzbot reported below: ------------[ cut here ]------------ kernel BUG at fs/f2fs/file.c:1243! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 5354 Comm: syz.0.0 Not tainted 6.17.0-rc1-syzkaller-00211-g90d970cade8e #0 PREEMPT(full) RIP: 0010:f2fs_truncate_hole+0x69e/0x6c0 fs/f2fs/file.c:1243 Call Trace: <TASK> f2fs_punch_hole+0x2db/0x330 fs/f2fs/file.c:1306 f2fs_fallocate+0x546/0x990 fs/f2fs/file.c:2018 vfs_fallocate+0x666/0x7e0 fs/open.c:342 ksys_fallocate fs/open.c:366 [inline] __do_sys_fallocate fs/open.c:371 [inline] __se_sys_fallocate fs/open.c:369 [inline] __x64_sys_fallocate+0xc0/0x110 fs/open.c:369 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1e65f8ebe9 w/ a fuzzed image, f2fs may encounter panic due to it detects inconsistent truncation range in direct node in f2fs_truncate_hole(). The root cause is: a non-inode dnode may has the same footer.ino and footer.nid, so the dnode will be parsed as an inode, then ADDRS_PER_PAGE() may return wrong blkaddr count which may be 923 typically, by chance, dn.ofs_in_node is equal to 923, then count can be calculated to 0 in below statement, later it will trigger panic w/ f2fs_bug_on(, count == 0 || ...). count = min(end_offset - dn.ofs_in_node, pg_end - pg_start); This patch introduces a new node_type NODE_TYPE_NON_INODE, then allowing passing the new_type to sanity_check_node_footer in f2fs_get_node_folio() to detect corruption that a non-inode dnode has the same footer.ino and footer.nid. Scripts to reproduce: mkfs.f2fs -f /dev/vdb mount /dev/vdb /mnt/f2fs touch /mnt/f2fs/foo touch /mnt/f2fs/bar dd if=/dev/zero of=/mnt/f2fs/foo bs=1M count=8 umount /mnt/f2fs inject.f2fs --node --mb i_nid --nid 4 --idx 0 --val 5 /dev/vdb mount /dev/vdb /mnt/f2fs xfs_io /mnt/f2fs/foo -c "fpunch 6984k 4k"
CVE-2025-40013 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: ASoC: qcom: audioreach: fix potential null pointer dereference It is possible that the topology parsing function audioreach_widget_load_module_common() could return NULL or an error pointer. Add missing NULL check so that we do not dereference it.
CVE-2023-54158 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: btrfs: don't free qgroup space unless specified Boris noticed in his simple quotas testing that he was getting a leak with Sweet Tea's change to subvol create that stopped doing a transaction commit. This was just a side effect of that change. In the delayed inode code we have an optimization that will free extra reservations if we think we can pack a dir item into an already modified leaf. Previously this wouldn't be triggered in the subvolume create case because we'd commit the transaction, it was still possible but much harder to trigger. It could actually be triggered if we did a mkdir && subvol create with qgroups enabled. This occurs because in btrfs_insert_delayed_dir_index(), which gets called when we're adding the dir item, we do the following: btrfs_block_rsv_release(fs_info, trans->block_rsv, bytes, NULL); if we're able to skip reserving space. The problem here is that trans->block_rsv points at the temporary block rsv for the subvolume create, which has qgroup reservations in the block rsv. This is a problem because btrfs_block_rsv_release() will do the following: if (block_rsv->qgroup_rsv_reserved >= block_rsv->qgroup_rsv_size) { qgroup_to_release = block_rsv->qgroup_rsv_reserved - block_rsv->qgroup_rsv_size; block_rsv->qgroup_rsv_reserved = block_rsv->qgroup_rsv_size; } The temporary block rsv just has ->qgroup_rsv_reserved set, ->qgroup_rsv_size == 0. The optimization in btrfs_insert_delayed_dir_index() sets ->qgroup_rsv_reserved = 0. Then later on when we call btrfs_subvolume_release_metadata() which has btrfs_block_rsv_release(fs_info, rsv, (u64)-1, &qgroup_to_release); btrfs_qgroup_convert_reserved_meta(root, qgroup_to_release); qgroup_to_release is set to 0, and we do not convert the reserved metadata space. The problem here is that the block rsv code has been unconditionally messing with ->qgroup_rsv_reserved, because the main place this is used is delalloc, and any time we call btrfs_block_rsv_release() we do it with qgroup_to_release set, and thus do the proper accounting. The subvolume code is the only other code that uses the qgroup reservation stuff, but it's intermingled with the above optimization, and thus was getting its reservation freed out from underneath it and thus leaking the reserved space. The solution is to simply not mess with the qgroup reservations if we don't have qgroup_to_release set. This works with the existing code as anything that messes with the delalloc reservations always have qgroup_to_release set. This fixes the leak that Boris was observing.