CVE-2022-48628

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

ceph: drop messages from MDS when unmounting

When unmounting all the dirty buffers will be flushed and after

the last osd request is finished the last reference of the i_count

will be released. Then it will flush the dirty cap/snap to MDSs,

and the unmounting won't wait the possible acks, which will ihold

the inodes when updating the metadata locally but makes no sense

any more, of this. This will make the evict_inodes() to skip these

inodes.

If encrypt is enabled the kernel generate a warning when removing

the encrypt keys when the skipped inodes still hold the keyring:

WARNING: CPU: 4 PID: 168846 at fs/crypto/keyring.c:242 fscrypt_destroy_keyring+0x7e/0xd0

CPU: 4 PID: 168846 Comm: umount Tainted: G S 6.1.0-rc5-ceph-g72ead199864c #1

Hardware name: Supermicro SYS-5018R-WR/X10SRW-F, BIOS 2.0 12/17/2015

RIP: 0010:fscrypt_destroy_keyring+0x7e/0xd0

RSP: 0018:ffffc9000b277e28 EFLAGS: 00010202

RAX: 0000000000000002 RBX: ffff88810d52ac00 RCX: ffff88810b56aa00

RDX: 0000000080000000 RSI: ffffffff822f3a09 RDI: ffff888108f59000

RBP: ffff8881d394fb88 R08: 0000000000000028 R09: 0000000000000000

R10: 0000000000000001 R11: 11ff4fe6834fcd91 R12: ffff8881d394fc40

R13: ffff888108f59000 R14: ffff8881d394f800 R15: 0000000000000000

FS: 00007fd83f6f1080(0000) GS:ffff88885fd00000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 00007f918d417000 CR3: 000000017f89a005 CR4: 00000000003706e0

DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000

DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Call Trace:

<TASK>

generic_shutdown_super+0x47/0x120

kill_anon_super+0x14/0x30

ceph_kill_sb+0x36/0x90 [ceph]

deactivate_locked_super+0x29/0x60

cleanup_mnt+0xb8/0x140

task_work_run+0x67/0xb0

exit_to_user_mode_prepare+0x23d/0x240

syscall_exit_to_user_mode+0x25/0x60

do_syscall_64+0x40/0x80

entry_SYSCALL_64_after_hwframe+0x63/0xcd

RIP: 0033:0x7fd83dc39e9b

Later the kernel will crash when iput() the inodes and dereferencing

the "sb->s_master_keys", which has been released by the

generic_shutdown_super().