Affected: Alpaquita:stream: linux-lts

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

ext4: fix rbtree traversal bug in ext4_mb_use_preallocated

During allocations, while looking for preallocations(PA) in the per inode rbtree, we can't do a direct traversal of the tree because ext4_mb_discard_group_preallocation() can paralelly mark the pa deleted and that can cause direct traversal to skip some entries. This was leading to a BUG_ON() being hit [1] when we missed a PA that could satisfy our request and ultimately tried to create a new PA that would overlap with the missed one.

To makes sure we handle that case while still keeping the performance of the rbtree, we make use of the fact that the only pa that could possibly overlap the original goal start is the one that satisfies the below conditions:

1. It must have it's logical start immediately to the left of (ie less than) original logical start.

2. It must not be deleted

To find this pa we use the following traversal method:

1. Descend into the rbtree normally to find the immediate neighboring PA. Here we keep descending irrespective of if the PA is deleted or if it overlaps with our request etc. The goal is to find an immediately adjacent PA.

2. If the found PA is on right of original goal, use rb_prev() to find the left adjacent PA.

3. Check if this PA is deleted and keep moving left with rb_prev() until a non deleted PA is found.

4. This is the PA we are looking for. Now we can check if it can satisfy the original request…

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

ext4: fix rbtree traversal bug in ext4_mb_use_preallocated

During allocations, while looking for preallocations(PA) in the per inode rbtree, we can't do a direct traversal of the tree because ext4_mb_discard_group_preallocation() can paralelly mark the pa deleted and that can cause direct traversal to skip some entries. This was leading to a BUG_ON() being hit [1] when we missed a PA that could satisfy our request and ultimately tried to create a new PA that would overlap with the missed one.

To makes sure we handle that case while still keeping the performance of the rbtree, we make use of the fact that the only pa that could possibly overlap the original goal start is the one that satisfies the below conditions:

1. It must have it's logical start immediately to the left of (ie less than) original logical start.

2. It must not be deleted

To find this pa we use the following traversal method:

1. Descend into the rbtree normally to find the immediate neighboring PA. Here we keep descending irrespective of if the PA is deleted or if it overlaps with our request etc. The goal is to find an immediately adjacent PA.

2. If the found PA is on right of original goal, use rb_prev() to find the left adjacent PA.

3. Check if this PA is deleted and keep moving left with rb_prev() until a non deleted PA is found.

4. This is the PA we are looking for. Now we can check if it can satisfy the original request…

kernel: Bluetooth BR/EDR PIN Pairing procedure is vulnerable to an impersonation attack kernel: ovl: fix warning in ovl_create_real() kernel: memcg does not limit the number of POSIX file locks allowing memory exhaustion kernel: vmwgfx: NULL pointer dereference in vmw_cmd_dx_define_query kernel: integer overflow in l2cap_config_req() in net/bluetooth/l2cap_core.c kernel: i2c: mlxbf: prevent stack overflow in mlxbf_i2c_smbus_start_transaction() kernel: Bluetooth: L2CAP: Fix u8 overflow kernel: hwmon: (coretemp) fix pci device refcount leak in nv1a_ram_new() kernel: tracing: Fix sleeping function called from invalid context on RT kernel kernel: net: mdio: unexport __init-annotated mdio_bus_init() kernel: arm64: ftrace: consistently handle PLTs. kernel: mm/uffd: fix pte marker when fork() without fork event kernel: Bluetooth: Fix a buffer overflow in mgmt_mesh_add() kernel: tty: n_gsm: add sanity check for gsm->receive in gsm_receive_buf() kernel: ftrace: Fix NULL pointer dereference in is_ftrace_trampoline when ftrace is dead kernel: tee: add overflow check in register_shm_helper() kernel: tty: n_gsm: fix deadlock and link starvation in outgoing data path kernel: PM: hibernate: defer device probing when resuming from hibernation kernel: ext4: don't allow journal inode to have encrypt flag kernel: ext4: fix delayed allocation bug in ext4_clu_mapped for bigalloc + inline kernel: erofs: fix order >= MAX_ORDER warning due to crafted negative i_size kernel: perf/x86/intel/uncore: F…

Security update for the Linux Kernel

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-azure-edge, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:18.04:LTS: linux-gcp-5.3, Ubuntu:18.04:LTS: linux-gke-4.15, Ubuntu:18.04:LTS: linux-gke-5.4 and 79 more

In the Linux kernel, the following vulnerability has been resolved: ext4: fix rbtree traversal bug in ext4_mb_use_preallocated During allocations, while looking for preallocations(PA) in the per inode rbtree, we can't do a direct traversal of the tree because ext4_mb_discard_group_preallocation() can paralelly mark the pa deleted and that can cause direct traversal to skip some entries. This was leading to a BUG_ON() being hit [1] when we missed a PA that could satisfy our request and ultimately tried to create a new PA that would overlap with the missed one. To makes sure we handle that case while still keeping the performance of the rbtree, we make use of the fact that the only pa that could possibly overlap the original goal start is the one that satisfies the below conditions: 1. It must have it's logical start immediately to the left of (ie less than) original logical start. 2. It must not be deleted To find this pa we use the following traversal method: 1. Descend into the rbtree normally to find the immediate neighboring PA. Here we keep descending irrespective of if the PA is deleted or if it overlaps with our request etc. The goal is to find an immediately adjacent PA. 2. If the found PA is on right of original goal, use rb_prev() to find the left adjacent PA. 3. Check if this PA is deleted and keep moving left with rb_prev() until a non deleted PA is found. 4. This is the PA we are looking for. Now we can check if it can satisfy the original request and proce…

Ein lokaler Angreifer kann mehrere Schwachstellen in Linux Kernel ausnutzen, um einen Denial of Service Angriff durchzuführen.