Affected: Alpaquita:stream: linux-lts

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

btrfs: fix race between quota rescan and disable leading to NULL pointer deref

If we have one task trying to start the quota rescan worker while another one is trying to disable quotas, we can end up hitting a race that results in the quota rescan worker doing a NULL pointer dereference. The steps for this are the following:

1) Quotas are enabled;

2) Task A calls the quota rescan ioctl and enters btrfs_qgroup_rescan(). It calls qgroup_rescan_init() which returns 0 (success) and then joins a transaction and commits it;

3) Task B calls the quota disable ioctl and enters btrfs_quota_disable(). It clears the bit BTRFS_FS_QUOTA_ENABLED from fs_info->flags and calls btrfs_qgroup_wait_for_completion(), which returns immediately since the rescan worker is not yet running. Then it starts a transaction and locks fs_info->qgroup_ioctl_lock;

4) Task A queues the rescan worker, by calling btrfs_queue_work();

5) The rescan worker starts, and calls rescan_should_stop() at the start of its while loop, which results in 0 iterations of the loop, since the flag BTRFS_FS_QUOTA_ENABLED was cleared from fs_info->flags by task B at step 3);

6) Task B sets fs_info->quota_root to NULL;

7) The rescan worker tries to start a transaction and uses fs_info->quota_root as the root argument for btrfs_start_transaction(). This results in a NULL pointer dereference down the call chain of btrfs_sta…

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

btrfs: fix race between quota rescan and disable leading to NULL pointer deref

If we have one task trying to start the quota rescan worker while another one is trying to disable quotas, we can end up hitting a race that results in the quota rescan worker doing a NULL pointer dereference. The steps for this are the following:

1) Quotas are enabled;

2) Task A calls the quota rescan ioctl and enters btrfs_qgroup_rescan(). It calls qgroup_rescan_init() which returns 0 (success) and then joins a transaction and commits it;

3) Task B calls the quota disable ioctl and enters btrfs_quota_disable(). It clears the bit BTRFS_FS_QUOTA_ENABLED from fs_info->flags and calls btrfs_qgroup_wait_for_completion(), which returns immediately since the rescan worker is not yet running. Then it starts a transaction and locks fs_info->qgroup_ioctl_lock;

4) Task A queues the rescan worker, by calling btrfs_queue_work();

5) The rescan worker starts, and calls rescan_should_stop() at the start of its while loop, which results in 0 iterations of the loop, since the flag BTRFS_FS_QUOTA_ENABLED was cleared from fs_info->flags by task B at step 3);

6) Task B sets fs_info->quota_root to NULL;

7) The rescan worker tries to start a transaction and uses fs_info->quota_root as the root argument for btrfs_start_transaction(). This results in a NULL pointer dereference down the call chain of btrfs_sta…

Affected: openEuler:22.03-LTS-SP1: kernel

The Linux Kernel, the operating system core itself. Security Fix(es): In the Linux kernel, the following vulnerability has been resolved: ibmvnic: don't release napi in __ibmvnic_open() If __ibmvnic_open() encounters an error such as when setting link state, it calls release_resources() which frees the napi structures needlessly. Instead, have __ibmvnic_open() only clean up the work it did so far (i.e. disable napi and irqs) and leave the rest to the callers. If caller of __ibmvnic_open() is ibmvnic_open(), it should release the resources immediately. If the caller is do_reset() or do_hard_reset(), they will release the resources on the next reset. This fixes following crash that occurred when running the drmgr command several times to add/remove a vnic interface: [102056] ibmvnic 30000003 env3: Disabling rx_scrq[6] irq [102056] ibmvnic 30000003 env3: Disabling rx_scrq[7] irq [102056] ibmvnic 30000003 env3: Replenished 8 pools Kernel attempted to read user page (10) - exploit attempt? (uid: 0) BUG: Kernel NULL pointer dereference on read at 0x00000010 Faulting instruction address: 0xc000000000a3c840 Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries ... CPU: 9 PID: 102056 Comm: kworker/9:2 Kdump: loaded Not tainted 5.16.0-rc5-autotest-g6441998e2e37 #1 Workqueue: events_long __ibmvnic_reset [ibmvnic] NIP: c000000000a3c840 LR: c0080000029b5378 CTR: c000000000a3c820 REGS: c0000000548e37e…

Security update for the Linux Kernel

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.4, Ubuntu:18.04:LTS: linux-azure-5.4, Ubuntu:18.04:LTS: linux-gcp-5.4, Ubuntu:18.04:LTS: linux-hwe-5.4, Ubuntu:18.04:LTS: linux-ibm-5.4, Ubuntu:18.04:LTS: linux-oracle-5.4, Ubuntu:18.04:LTS: linux-raspi-5.4, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3 and 114 more

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix race between quota rescan and disable leading to NULL pointer deref If we have one task trying to start the quota rescan worker while another one is trying to disable quotas, we can end up hitting a race that results in the quota rescan worker doing a NULL pointer dereference. The steps for this are the following: 1) Quotas are enabled; 2) Task A calls the quota rescan ioctl and enters btrfs_qgroup_rescan(). It calls qgroup_rescan_init() which returns 0 (success) and then joins a transaction and commits it; 3) Task B calls the quota disable ioctl and enters btrfs_quota_disable(). It clears the bit BTRFS_FS_QUOTA_ENABLED from fs_info->flags and calls btrfs_qgroup_wait_for_completion(), which returns immediately since the rescan worker is not yet running. Then it starts a transaction and locks fs_info->qgroup_ioctl_lock; 4) Task A queues the rescan worker, by calling btrfs_queue_work(); 5) The rescan worker starts, and calls rescan_should_stop() at the start of its while loop, which results in 0 iterations of the loop, since the flag BTRFS_FS_QUOTA_ENABLED was cleared from fs_info->flags by task B at step 3); 6) Task B sets fs_info->quota_root to NULL; 7) The rescan worker tries to start a transaction and uses fs_info->quota_root as the root argument for btrfs_start_transaction(). This results in a NULL pointer dereference down the call chain of btrfs_start_transa…

Ein lokaler Angreifer kann mehrere Schwachstellen im Linux-Kernel ausnutzen, um einen Denial-of-Service-Zustand zu erzeugen oder einen unspezifischen Angriff durchzuführen.