In the Linux kernel, the following vulnerability has been resolved:
net/smc: fix LGR and link use-after-free issue
We encountered a LGR/link use-after-free issue, which manifested as
the LGR/link refcnt reaching 0 early and entering the clear process,
making resource access unsafe.
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 14 PID: 107447 at lib/refcount.c:25 refcount_warn_saturate+0x9c/0x140
Workqueue: events smc_lgr_terminate_work [smc]
Call trace:
refcount_warn_saturate+0x9c/0x140
__smc_lgr_terminate.part.45+0x2a8/0x370 [smc]
smc_lgr_terminate_work+0x28/0x30 [smc]
process_one_work+0x1b8/0x420
worker_thread+0x158/0x510
kthread+0x114/0x118
or
refcount_t: underflow; use-after-free.
WARNING: CPU: 6 PID: 93140 at lib/refcount.c:28 refcount_warn_saturate+0xf0/0x140
Workqueue: smc_hs_wq smc_listen_work [smc]
Call trace:
refcount_warn_saturate+0xf0/0x140
smcr_link_put+0x1cc/0x1d8 [smc]
smc_conn_free+0x110/0x1b0 [smc]
smc_conn_abort+0x50/0x60 [smc]
smc_listen_find_device+0x75c/0x790 [smc]
smc_listen_work+0x368/0x8a0 [smc]
process_one_work+0x1b8/0x420
worker_thread+0x158/0x510
kthread+0x114/0x118
It is caused by repeated release of LGR/link refcnt. One suspect is that
smc_conn_free() is called repeatedly because some smc_conn_free() from
server listening path are not protected by sock lock.
e.g.
Calls under socklock | smc_listen_work
-------------------------------------------------------
lock_sock(sk) | smc_conn_abort
smc_conn_free | \- smc_conn_free
\- smcr_link_put | \- smcr_link_put (duplicated)
release_sock(sk)
So here add sock lock protection in smc_listen_work() path, making it
exclusive with other connection operations.
In the Linux kernel, the following vulnerability has been resolved:
net/smc: initialize close_work early to avoid warning
We encountered a warning that close_work was canceled before
initialization.
WARNING: CPU: 7 PID: 111103 at kernel/workqueue.c:3047 __flush_work+0x19e/0x1b0
Workqueue: events smc_lgr_terminate_work [smc]
RIP: 0010:__flush_work+0x19e/0x1b0
Call Trace:
? __wake_up_common+0x7a/0x190
? work_busy+0x80/0x80
__cancel_work_timer+0xe3/0x160
smc_close_cancel_work+0x1a/0x70 [smc]
smc_close_active_abort+0x207/0x360 [smc]
__smc_lgr_terminate.part.38+0xc8/0x180 [smc]
process_one_work+0x19e/0x340
worker_thread+0x30/0x370
? process_one_work+0x340/0x340
kthread+0x117/0x130
? __kthread_cancel_work+0x50/0x50
ret_from_fork+0x22/0x30
This is because when smc_close_cancel_work is triggered, e.g. the RDMA
driver is rmmod and the LGR is terminated, the conn->close_work is
flushed before initialization, resulting in WARN_ON(!work->func).
__smc_lgr_terminate | smc_connect_{rdma|ism}
-------------------------------------------------------------
| smc_conn_create
| \- smc_lgr_register_conn
for conn in lgr->conns_all |
\- smc_conn_kill |
\- smc_close_active_abort |
\- smc_close_cancel_work |
\- cancel_work_sync |
\- __flush_work |
(close_work) |
| smc_close_init
| \- INIT_WORK(&close_work)
So fix this by initializing close_work before establishing the
connection.
In the Linux kernel, the following vulnerability has been resolved:
tipc: Fix use-after-free of kernel socket in cleanup_bearer().
syzkaller reported a use-after-free of UDP kernel socket
in cleanup_bearer() without repro. [0][1]
When bearer_disable() calls tipc_udp_disable(), cleanup
of the UDP kernel socket is deferred by work calling
cleanup_bearer().
tipc_exit_net() waits for such works to finish by checking
tipc_net(net)->wq_count. However, the work decrements the
count too early before releasing the kernel socket,
unblocking cleanup_net() and resulting in use-after-free.
Let's move the decrement after releasing the socket in
cleanup_bearer().
[0]:
ref_tracker: net notrefcnt@000000009b3d1faf has 1/1 users at
sk_alloc+0x438/0x608
inet_create+0x4c8/0xcb0
__sock_create+0x350/0x6b8
sock_create_kern+0x58/0x78
udp_sock_create4+0x68/0x398
udp_sock_create+0x88/0xc8
tipc_udp_enable+0x5e8/0x848
__tipc_nl_bearer_enable+0x84c/0xed8
tipc_nl_bearer_enable+0x38/0x60
genl_family_rcv_msg_doit+0x170/0x248
genl_rcv_msg+0x400/0x5b0
netlink_rcv_skb+0x1dc/0x398
genl_rcv+0x44/0x68
netlink_unicast+0x678/0x8b0
netlink_sendmsg+0x5e4/0x898
____sys_sendmsg+0x500/0x830
[1]:
BUG: KMSAN: use-after-free in udp_hashslot include/net/udp.h:85 [inline]
BUG: KMSAN: use-after-free in udp_lib_unhash+0x3b8/0x930 net/ipv4/udp.c:1979
udp_hashslot include/net/udp.h:85 [inline]
udp_lib_unhash+0x3b8/0x930 net/ipv4/udp.c:1979
sk_common_release+0xaf/0x3f0 net/core/sock.c:3820
inet_release+0x1e0/0x260 net/ipv4/af_inet.c:437
inet6_release+0x6f/0xd0 net/ipv6/af_inet6.c:489
__sock_release net/socket.c:658 [inline]
sock_release+0xa0/0x210 net/socket.c:686
cleanup_bearer+0x42d/0x4c0 net/tipc/udp_media.c:819
process_one_work kernel/workqueue.c:3229 [inline]
process_scheduled_works+0xcaf/0x1c90 kernel/workqueue.c:3310
worker_thread+0xf6c/0x1510 kernel/workqueue.c:3391
kthread+0x531/0x6b0 kernel/kthread.c:389
ret_from_fork+0x60/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:244
Uninit was created at:
slab_free_hook mm/slub.c:2269 [inline]
slab_free mm/slub.c:4580 [inline]
kmem_cache_free+0x207/0xc40 mm/slub.c:4682
net_free net/core/net_namespace.c:454 [inline]
cleanup_net+0x16f2/0x19d0 net/core/net_namespace.c:647
process_one_work kernel/workqueue.c:3229 [inline]
process_scheduled_works+0xcaf/0x1c90 kernel/workqueue.c:3310
worker_thread+0xf6c/0x1510 kernel/workqueue.c:3391
kthread+0x531/0x6b0 kernel/kthread.c:389
ret_from_fork+0x60/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:244
CPU: 0 UID: 0 PID: 54 Comm: kworker/0:2 Not tainted 6.12.0-rc1-00131-gf66ebf37d69c #7 91723d6f74857f70725e1583cba3cf4adc716cfa
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
Workqueue: events cleanup_bearer
In the Linux kernel, the following vulnerability has been resolved:
can: dev: can_set_termination(): allow sleeping GPIOs
In commit 6e86a1543c37 ("can: dev: provide optional GPIO based
termination support") GPIO based termination support was added.
For no particular reason that patch uses gpiod_set_value() to set the
GPIO. This leads to the following warning, if the systems uses a
sleeping GPIO, i.e. behind an I2C port expander:
| WARNING: CPU: 0 PID: 379 at /drivers/gpio/gpiolib.c:3496 gpiod_set_value+0x50/0x6c
| CPU: 0 UID: 0 PID: 379 Comm: ip Not tainted 6.11.0-20241016-1 #1 823affae360cc91126e4d316d7a614a8bf86236c
Replace gpiod_set_value() by gpiod_set_value_cansleep() to allow the
use of sleeping GPIOs.
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix Out-of-Bounds Write in ksmbd_vfs_stream_write
An offset from client could be a negative value, It could allows
to write data outside the bounds of the allocated buffer.
Note that this issue is coming when setting
'vfs objects = streams_xattr parameter' in ksmbd.conf.
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix Out-of-Bounds Read in ksmbd_vfs_stream_read
An offset from client could be a negative value, It could lead
to an out-of-bounds read from the stream_buf.
Note that this issue is coming when setting
'vfs objects = streams_xattr parameter' in ksmbd.conf.
In the Linux kernel, the following vulnerability has been resolved:
LoongArch: Add architecture specific huge_pte_clear()
When executing mm selftests run_vmtests.sh, there is such an error:
BUG: Bad page state in process uffd-unit-tests pfn:00000
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x0
flags: 0xffff0000002000(reserved|node=0|zone=0|lastcpupid=0xffff)
raw: 00ffff0000002000 ffffbf0000000008 ffffbf0000000008 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
Modules linked in: snd_seq_dummy snd_seq snd_seq_device rfkill vfat fat
virtio_balloon efi_pstore virtio_net pstore net_failover failover fuse
nfnetlink virtio_scsi virtio_gpu virtio_dma_buf dm_multipath efivarfs
CPU: 2 UID: 0 PID: 1913 Comm: uffd-unit-tests Not tainted 6.12.0 #184
Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
Stack : 900000047c8ac000 0000000000000000 9000000000223a7c 900000047c8ac000
900000047c8af690 900000047c8af698 0000000000000000 900000047c8af7d8
900000047c8af7d0 900000047c8af7d0 900000047c8af5b0 0000000000000001
0000000000000001 900000047c8af698 10b3c7d53da40d26 0000010000000000
0000000000000022 0000000fffffffff fffffffffe000000 ffff800000000000
000000000000002f 0000800000000000 000000017a6d4000 90000000028f8940
0000000000000000 0000000000000000 90000000025aa5e0 9000000002905000
0000000000000000 90000000028f8940 ffff800000000000 0000000000000000
0000000000000000 0000000000000000 9000000000223a94 000000012001839c
00000000000000b0 0000000000000004 0000000000000000 0000000000071c1d
...
Call Trace:
[<9000000000223a94>] show_stack+0x5c/0x180
[<9000000001c3fd64>] dump_stack_lvl+0x6c/0xa0
[<900000000056aa08>] bad_page+0x1a0/0x1f0
[<9000000000574978>] free_unref_folios+0xbf0/0xd20
[<90000000004e65cc>] folios_put_refs+0x1a4/0x2b8
[<9000000000599a0c>] free_pages_and_swap_cache+0x164/0x260
[<9000000000547698>] tlb_batch_pages_flush+0xa8/0x1c0
[<9000000000547f30>] tlb_finish_mmu+0xa8/0x218
[<9000000000543cb8>] exit_mmap+0x1a0/0x360
[<9000000000247658>] __mmput+0x78/0x200
[<900000000025583c>] do_exit+0x43c/0xde8
[<9000000000256490>] do_group_exit+0x68/0x110
[<9000000000256554>] sys_exit_group+0x1c/0x20
[<9000000001c413b4>] do_syscall+0x94/0x130
[<90000000002216d8>] handle_syscall+0xb8/0x158
Disabling lock debugging due to kernel taint
BUG: non-zero pgtables_bytes on freeing mm: -16384
On LoongArch system, invalid huge pte entry should be invalid_pte_table
or a single _PAGE_HUGE bit rather than a zero value. And it should be
the same with invalid pmd entry, since pmd_none() is called by function
free_pgd_range() and pmd_none() return 0 by huge_pte_clear(). So single
_PAGE_HUGE bit is also treated as a valid pte table and free_pte_range()
will be called in free_pmd_range().
free_pmd_range()
pmd = pmd_offset(pud, addr);
do {
next = pmd_addr_end(addr, end);
if (pmd_none_or_clear_bad(pmd))
continue;
free_pte_range(tlb, pmd, addr);
} while (pmd++, addr = next, addr != end);
Here invalid_pte_table is used for both invalid huge pte entry and
pmd entry.
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: free inode when ocfs2_get_init_inode() fails
syzbot is reporting busy inodes after unmount, for commit 9c89fe0af826
("ocfs2: Handle error from dquot_initialize()") forgot to call iput() when
new_inode() succeeded and dquot_initialize() failed.
In the Linux kernel, the following vulnerability has been resolved:
scsi: sg: Fix slab-use-after-free read in sg_release()
Fix a use-after-free bug in sg_release(), detected by syzbot with KASAN:
BUG: KASAN: slab-use-after-free in lock_release+0x151/0xa30
kernel/locking/lockdep.c:5838
__mutex_unlock_slowpath+0xe2/0x750 kernel/locking/mutex.c:912
sg_release+0x1f4/0x2e0 drivers/scsi/sg.c:407
In sg_release(), the function kref_put(&sfp->f_ref, sg_remove_sfp) is
called before releasing the open_rel_lock mutex. The kref_put() call may
decrement the reference count of sfp to zero, triggering its cleanup
through sg_remove_sfp(). This cleanup includes scheduling deferred work
via sg_remove_sfp_usercontext(), which ultimately frees sfp.
After kref_put(), sg_release() continues to unlock open_rel_lock and may
reference sfp or sdp. If sfp has already been freed, this results in a
slab-use-after-free error.
Move the kref_put(&sfp->f_ref, sg_remove_sfp) call after unlocking the
open_rel_lock mutex. This ensures:
- No references to sfp or sdp occur after the reference count is
decremented.
- Cleanup functions such as sg_remove_sfp() and
sg_remove_sfp_usercontext() can safely execute without impacting the
mutex handling in sg_release().
The fix has been tested and validated by syzbot. This patch closes the
bug reported at the following syzkaller link and ensures proper
sequencing of resource cleanup and mutex operations, eliminating the
risk of use-after-free errors in sg_release().