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

arm64: ftrace: consistently handle PLTs.

Sometimes it is necessary to use a PLT entry to call an ftrace trampoline. This is handled by ftrace_make_call() and ftrace_make_nop(), with each having *almost* identical logic, but this is not handled by ftrace_modify_call() since its introduction in commit:

3b23e4991fb66f6d ("arm64: implement ftrace with regs")

Due to this, if we ever were to call ftrace_modify_call() for a callsite which requires a PLT entry for a trampoline, then either:

a) If the old addr requires a trampoline, ftrace_modify_call() will use an out-of-range address to generate the 'old' branch instruction. This will result in warnings from aarch64_insn_gen_branch_imm() and ftrace_modify_code(), and no instructions will be modified. As ftrace_modify_call() will return an error, this will result in subsequent internal ftrace errors.

b) If the old addr does not require a trampoline, but the new addr does, ftrace_modify_call() will use an out-of-range address to generate the 'new' branch instruction. This will result in warnings from aarch64_insn_gen_branch_imm(), and ftrace_modify_code() will replace the 'old' branch with a BRK. This will result in a kernel panic when this BRK is later executed.

Practically speaking, case (a) is vastly more likely than case (b), and typically this will result in internal ftrace errors that don't necessarily affect the rest of t…

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

arm64: ftrace: consistently handle PLTs.

Sometimes it is necessary to use a PLT entry to call an ftrace trampoline. This is handled by ftrace_make_call() and ftrace_make_nop(), with each having *almost* identical logic, but this is not handled by ftrace_modify_call() since its introduction in commit:

3b23e4991fb66f6d ("arm64: implement ftrace with regs")

Due to this, if we ever were to call ftrace_modify_call() for a callsite which requires a PLT entry for a trampoline, then either:

a) If the old addr requires a trampoline, ftrace_modify_call() will use an out-of-range address to generate the 'old' branch instruction. This will result in warnings from aarch64_insn_gen_branch_imm() and ftrace_modify_code(), and no instructions will be modified. As ftrace_modify_call() will return an error, this will result in subsequent internal ftrace errors.

b) If the old addr does not require a trampoline, but the new addr does, ftrace_modify_call() will use an out-of-range address to generate the 'new' branch instruction. This will result in warnings from aarch64_insn_gen_branch_imm(), and ftrace_modify_code() will replace the 'old' branch with a BRK. This will result in a kernel panic when this BRK is later executed.

Practically speaking, case (a) is vastly more likely than case (b), and typically this will result in internal ftrace errors that don't necessarily affect the rest of t…

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 92 more

In the Linux kernel, the following vulnerability has been resolved: arm64: ftrace: consistently handle PLTs. Sometimes it is necessary to use a PLT entry to call an ftrace trampoline. This is handled by ftrace_make_call() and ftrace_make_nop(), with each having *almost* identical logic, but this is not handled by ftrace_modify_call() since its introduction in commit: 3b23e4991fb66f6d ("arm64: implement ftrace with regs") Due to this, if we ever were to call ftrace_modify_call() for a callsite which requires a PLT entry for a trampoline, then either: a) If the old addr requires a trampoline, ftrace_modify_call() will use an out-of-range address to generate the 'old' branch instruction. This will result in warnings from aarch64_insn_gen_branch_imm() and ftrace_modify_code(), and no instructions will be modified. As ftrace_modify_call() will return an error, this will result in subsequent internal ftrace errors. b) If the old addr does not require a trampoline, but the new addr does, ftrace_modify_call() will use an out-of-range address to generate the 'new' branch instruction. This will result in warnings from aarch64_insn_gen_branch_imm(), and ftrace_modify_code() will replace the 'old' branch with a BRK. This will result in a kernel panic when this BRK is later executed. Practically speaking, case (a) is vastly more likely than case (b), and typically this will result in internal ftrace errors that don't necessarily affect the rest of the syst…