Affected: Linux

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

md/raid5-cache: fix null-ptr-deref for r5l_flush_stripe_to_raid()

r5l_flush_stripe_to_raid() will check if the list 'flushing_ios' is empty, and then submit 'flush_bio', however, r5l_log_flush_endio() is clearing the list first and then clear the bio, which will cause null-ptr-deref:

T1: submit flush io raid5d handle_active_stripes r5l_flush_stripe_to_raid // list is empty // add 'io_end_ios' to the list bio_init submit_bio // io1

T2: io1 is done r5l_log_flush_endio list_splice_tail_init // clear the list T3: submit new flush io ... r5l_flush_stripe_to_raid // list is empty // add 'io_end_ios' to the list bio_init bio_uninit // clear bio->bi_blkg submit_bio // null-ptr-deref

Fix this problem by clearing bio before clearing the list in r5l_log_flush_endio().

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…