In the Linux kernel, the following vulnerability has been resolved:
mISDN: annotate data-race around dev->work
dev->work can re read locklessly in mISDN_read()
and mISDN_poll(). Add READ_ONCE()/WRITE_ONCE() annotations.
BUG: KCSAN: data-race in mISDN_ioctl / mISDN_read
write to 0xffff88812d848280 of 4 bytes by task 10864 on cpu 1:
misdn_add_timer drivers/isdn/mISDN/timerdev.c:175 [inline]
mISDN_ioctl+0x2fb/0x550 drivers/isdn/mISDN/timerdev.c:233
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xce/0x140 fs/ioctl.c:583
__x64_sys_ioctl+0x43/0x50 fs/ioctl.c:583
x64_sys_call+0x14b0/0x3000 arch/x86/include/generated/asm/syscalls_64.h:17
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xd8/0x2c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
read to 0xffff88812d848280 of 4 bytes by task 10857 on cpu 0:
mISDN_read+0x1f2/0x470 drivers/isdn/mISDN/timerdev.c:112
do_loop_readv_writev fs/read_write.c:847 [inline]
vfs_readv+0x3fb/0x690 fs/read_write.c:1020
do_readv+0xe7/0x210 fs/read_write.c:1080
__do_sys_readv fs/read_write.c:1165 [inline]
__se_sys_readv fs/read_write.c:1162 [inline]
__x64_sys_readv+0x45/0x50 fs/read_write.c:1162
x64_sys_call+0x2831/0x3000 arch/x86/include/generated/asm/syscalls_64.h:20
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xd8/0x2c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
value changed: 0x00000000 -> 0x00000001
In the Linux kernel, the following vulnerability has been resolved:
sctp: move SCTP_CMD_ASSOC_SHKEY right after SCTP_CMD_PEER_INIT
A null-ptr-deref was reported in the SCTP transmit path when SCTP-AUTH key
initialization fails:
==================================================================
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
CPU: 0 PID: 16 Comm: ksoftirqd/0 Tainted: G W 6.6.0 #2
RIP: 0010:sctp_packet_bundle_auth net/sctp/output.c:264 [inline]
RIP: 0010:sctp_packet_append_chunk+0xb36/0x1260 net/sctp/output.c:401
Call Trace:
sctp_packet_transmit_chunk+0x31/0x250 net/sctp/output.c:189
sctp_outq_flush_data+0xa29/0x26d0 net/sctp/outqueue.c:1111
sctp_outq_flush+0xc80/0x1240 net/sctp/outqueue.c:1217
sctp_cmd_interpreter.isra.0+0x19a5/0x62c0 net/sctp/sm_sideeffect.c:1787
sctp_side_effects net/sctp/sm_sideeffect.c:1198 [inline]
sctp_do_sm+0x1a3/0x670 net/sctp/sm_sideeffect.c:1169
sctp_assoc_bh_rcv+0x33e/0x640 net/sctp/associola.c:1052
sctp_inq_push+0x1dd/0x280 net/sctp/inqueue.c:88
sctp_rcv+0x11ae/0x3100 net/sctp/input.c:243
sctp6_rcv+0x3d/0x60 net/sctp/ipv6.c:1127
The issue is triggered when sctp_auth_asoc_init_active_key() fails in
sctp_sf_do_5_1C_ack() while processing an INIT_ACK. In this case, the
command sequence is currently:
- SCTP_CMD_PEER_INIT
- SCTP_CMD_TIMER_STOP (T1_INIT)
- SCTP_CMD_TIMER_START (T1_COOKIE)
- SCTP_CMD_NEW_STATE (COOKIE_ECHOED)
- SCTP_CMD_ASSOC_SHKEY
- SCTP_CMD_GEN_COOKIE_ECHO
If SCTP_CMD_ASSOC_SHKEY fails, asoc->shkey remains NULL, while
asoc->peer.auth_capable and asoc->peer.peer_chunks have already been set by
SCTP_CMD_PEER_INIT. This allows a DATA chunk with auth = 1 and shkey = NULL
to be queued by sctp_datamsg_from_user().
Since command interpretation stops on failure, no COOKIE_ECHO should been
sent via SCTP_CMD_GEN_COOKIE_ECHO. However, the T1_COOKIE timer has already
been started, and it may enqueue a COOKIE_ECHO into the outqueue later. As
a result, the DATA chunk can be transmitted together with the COOKIE_ECHO
in sctp_outq_flush_data(), leading to the observed issue.
Similar to the other places where it calls sctp_auth_asoc_init_active_key()
right after sctp_process_init(), this patch moves the SCTP_CMD_ASSOC_SHKEY
immediately after SCTP_CMD_PEER_INIT, before stopping T1_INIT and starting
T1_COOKIE. This ensures that if shared key generation fails, authenticated
DATA cannot be sent. It also allows the T1_INIT timer to retransmit INIT,
giving the client another chance to process INIT_ACK and retry key setup.
In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Fix data-race warning and potential load/store tearing
Fix the following:
BUG: KCSAN: data-race in rxrpc_peer_keepalive_worker / rxrpc_send_data_packet
which is reporting an issue with the reads and writes to ->last_tx_at in:
conn->peer->last_tx_at = ktime_get_seconds();
and:
keepalive_at = peer->last_tx_at + RXRPC_KEEPALIVE_TIME;
The lockless accesses to these to values aren't actually a problem as the
read only needs an approximate time of last transmission for the purposes
of deciding whether or not the transmission of a keepalive packet is
warranted yet.
Also, as ->last_tx_at is a 64-bit value, tearing can occur on a 32-bit
arch.
Fix both of these by switching to an unsigned int for ->last_tx_at and only
storing the LSW of the time64_t. It can then be reconstructed at need
provided no more than 68 years has elapsed since the last transmission.
In the Linux kernel, the following vulnerability has been resolved:
nvmet-tcp: add bounds checks in nvmet_tcp_build_pdu_iovec
nvmet_tcp_build_pdu_iovec() could walk past cmd->req.sg when a PDU
length or offset exceeds sg_cnt and then use bogus sg->length/offset
values, leading to _copy_to_iter() GPF/KASAN. Guard sg_idx, remaining
entries, and sg->length/offset before building the bvec.
In the Linux kernel, the following vulnerability has been resolved:
net/sched: qfq: Use cl_is_active to determine whether class is active in qfq_rm_from_ag
This is more of a preventive patch to make the code more consistent and
to prevent possible exploits that employ child qlen manipulations on qfq.
use cl_is_active instead of relying on the child qdisc's qlen to determine
class activation.
In the Linux kernel, the following vulnerability has been resolved:
can: usb_8dev: usb_8dev_read_bulk_callback(): fix URB memory leak
Fix similar memory leak as in commit 7352e1d5932a ("can: gs_usb:
gs_usb_receive_bulk_callback(): fix URB memory leak").
In usb_8dev_open() -> usb_8dev_start(), the URBs for USB-in transfers are
allocated, added to the priv->rx_submitted anchor and submitted. In the
complete callback usb_8dev_read_bulk_callback(), the URBs are processed and
resubmitted. In usb_8dev_close() -> unlink_all_urbs() the URBs are freed by
calling usb_kill_anchored_urbs(&priv->rx_submitted).
However, this does not take into account that the USB framework unanchors
the URB before the complete function is called. This means that once an
in-URB has been completed, it is no longer anchored and is ultimately not
released in usb_kill_anchored_urbs().
Fix the memory leak by anchoring the URB in the
usb_8dev_read_bulk_callback() to the priv->rx_submitted anchor.
In the Linux kernel, the following vulnerability has been resolved:
scsi: core: Wake up the error handler when final completions race against each other
The fragile ordering between marking commands completed or failed so
that the error handler only wakes when the last running command
completes or times out has race conditions. These race conditions can
cause the SCSI layer to fail to wake the error handler, leaving I/O
through the SCSI host stuck as the error state cannot advance.
First, there is an memory ordering issue within scsi_dec_host_busy().
The write which clears SCMD_STATE_INFLIGHT may be reordered with reads
counting in scsi_host_busy(). While the local CPU will see its own
write, reordering can allow other CPUs in scsi_dec_host_busy() or
scsi_eh_inc_host_failed() to see a raised busy count, causing no CPU to
see a host busy equal to the host_failed count.
This race condition can be prevented with a memory barrier on the error
path to force the write to be visible before counting host busy
commands.
Second, there is a general ordering issue with scsi_eh_inc_host_failed(). By
counting busy commands before incrementing host_failed, it can race with a
final command in scsi_dec_host_busy(), such that scsi_dec_host_busy() does
not see host_failed incremented but scsi_eh_inc_host_failed() counts busy
commands before SCMD_STATE_INFLIGHT is cleared by scsi_dec_host_busy(),
resulting in neither waking the error handler task.
This needs the call to scsi_host_busy() to be moved after host_failed is
incremented to close the race condition.
In the Linux kernel, the following vulnerability has been resolved:
uacce: fix cdev handling in the cleanup path
When cdev_device_add fails, it internally releases the cdev memory,
and if cdev_device_del is then executed, it will cause a hang error.
To fix it, we check the return value of cdev_device_add() and clear
uacce->cdev to avoid calling cdev_device_del in the uacce_remove.
In the Linux kernel, the following vulnerability has been resolved:
migrate: correct lock ordering for hugetlb file folios
Syzbot has found a deadlock (analyzed by Lance Yang):
1) Task (5749): Holds folio_lock, then tries to acquire i_mmap_rwsem(read lock).
2) Task (5754): Holds i_mmap_rwsem(write lock), then tries to acquire
folio_lock.
migrate_pages()
-> migrate_hugetlbs()
-> unmap_and_move_huge_page() <- Takes folio_lock!
-> remove_migration_ptes()
-> __rmap_walk_file()
-> i_mmap_lock_read() <- Waits for i_mmap_rwsem(read lock)!
hugetlbfs_fallocate()
-> hugetlbfs_punch_hole() <- Takes i_mmap_rwsem(write lock)!
-> hugetlbfs_zero_partial_page()
-> filemap_lock_hugetlb_folio()
-> filemap_lock_folio()
-> __filemap_get_folio <- Waits for folio_lock!
The migration path is the one taking locks in the wrong order according to
the documentation at the top of mm/rmap.c. So expand the scope of the
existing i_mmap_lock to cover the calls to remove_migration_ptes() too.
This is (mostly) how it used to be after commit c0d0381ade79. That was
removed by 336bf30eb765 for both file & anon hugetlb pages when it should
only have been removed for anon hugetlb pages.