| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
s390/mm: Do not map lowcore with identity mapping
Since the identity mapping is pinned to address zero the lowcore is always
also mapped to address zero, this happens regardless of the relocate_lowcore
command line option. If the option is specified the lowcore is mapped
twice, instead of only once.
This means that NULL pointer accesses will succeed instead of causing an
exception (low address protection still applies, but covers only parts).
To fix this never map the first two pages of physical memory with the
identity mapping. |
| In the Linux kernel, the following vulnerability has been resolved:
atm: clip: Fix potential null-ptr-deref in to_atmarpd().
atmarpd is protected by RTNL since commit f3a0592b37b8 ("[ATM]: clip
causes unregister hang").
However, it is not enough because to_atmarpd() is called without RTNL,
especially clip_neigh_solicit() / neigh_ops->solicit() is unsleepable.
Also, there is no RTNL dependency around atmarpd.
Let's use a private mutex and RCU to protect access to atmarpd in
to_atmarpd(). |
| In the Linux kernel, the following vulnerability has been resolved:
genirq/irq_sim: Initialize work context pointers properly
Initialize `ops` member's pointers properly by using kzalloc() instead of
kmalloc() when allocating the simulation work context. Otherwise the
pointers contain random content leading to invalid dereferencing. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: target: Fix NULL pointer dereference in core_scsi3_decode_spec_i_port()
The function core_scsi3_decode_spec_i_port(), in its error code path,
unconditionally calls core_scsi3_lunacl_undepend_item() passing the
dest_se_deve pointer, which may be NULL.
This can lead to a NULL pointer dereference if dest_se_deve remains
unset.
SPC-3 PR SPEC_I_PT: Unable to locate dest_tpg
Unable to handle kernel paging request at virtual address dfff800000000012
Call trace:
core_scsi3_lunacl_undepend_item+0x2c/0xf0 [target_core_mod] (P)
core_scsi3_decode_spec_i_port+0x120c/0x1c30 [target_core_mod]
core_scsi3_emulate_pro_register+0x6b8/0xcd8 [target_core_mod]
target_scsi3_emulate_pr_out+0x56c/0x840 [target_core_mod]
Fix this by adding a NULL check before calling
core_scsi3_lunacl_undepend_item() |
| In the Linux kernel, the following vulnerability has been resolved:
platform/x86: dell_rbu: Fix list usage
Pass the correct list head to list_for_each_entry*() when looping through
the packet list.
Without this patch, reading the packet data via sysfs will show the data
incorrectly (because it starts at the wrong packet), and clearing the
packet list will result in a NULL pointer dereference. |
| In the Linux kernel, the following vulnerability has been resolved:
tipc: fix null-ptr-deref when acquiring remote ip of ethernet bearer
The reproduction steps:
1. create a tun interface
2. enable l2 bearer
3. TIPC_NL_UDP_GET_REMOTEIP with media name set to tun
tipc: Started in network mode
tipc: Node identity 8af312d38a21, cluster identity 4711
tipc: Enabled bearer <eth:syz_tun>, priority 1
Oops: general protection fault
KASAN: null-ptr-deref in range
CPU: 1 UID: 1000 PID: 559 Comm: poc Not tainted 6.16.0-rc1+ #117 PREEMPT
Hardware name: QEMU Ubuntu 24.04 PC
RIP: 0010:tipc_udp_nl_dump_remoteip+0x4a4/0x8f0
the ub was in fact a struct dev.
when bid != 0 && skip_cnt != 0, bearer_list[bid] may be NULL or
other media when other thread changes it.
fix this by checking media_id. |
| In the Linux kernel, the following vulnerability has been resolved:
sunrpc: handle SVC_GARBAGE during svc auth processing as auth error
tianshuo han reported a remotely-triggerable crash if the client sends a
kernel RPC server a specially crafted packet. If decoding the RPC reply
fails in such a way that SVC_GARBAGE is returned without setting the
rq_accept_statp pointer, then that pointer can be dereferenced and a
value stored there.
If it's the first time the thread has processed an RPC, then that
pointer will be set to NULL and the kernel will crash. In other cases,
it could create a memory scribble.
The server sunrpc code treats a SVC_GARBAGE return from svc_authenticate
or pg_authenticate as if it should send a GARBAGE_ARGS reply. RFC 5531
says that if authentication fails that the RPC should be rejected
instead with a status of AUTH_ERR.
Handle a SVC_GARBAGE return as an AUTH_ERROR, with a reason of
AUTH_BADCRED instead of returning GARBAGE_ARGS in that case. This
sidesteps the whole problem of touching the rpc_accept_statp pointer in
this situation and avoids the crash. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: target: iscsi: Fix timeout on deleted connection
NOPIN response timer may expire on a deleted connection and crash with
such logs:
Did not receive response to NOPIN on CID: 0, failing connection for I_T Nexus (null),i,0x00023d000125,iqn.2017-01.com.iscsi.target,t,0x3d
BUG: Kernel NULL pointer dereference on read at 0x00000000
NIP strlcpy+0x8/0xb0
LR iscsit_fill_cxn_timeout_err_stats+0x5c/0xc0 [iscsi_target_mod]
Call Trace:
iscsit_handle_nopin_response_timeout+0xfc/0x120 [iscsi_target_mod]
call_timer_fn+0x58/0x1f0
run_timer_softirq+0x740/0x860
__do_softirq+0x16c/0x420
irq_exit+0x188/0x1c0
timer_interrupt+0x184/0x410
That is because nopin response timer may be re-started on nopin timer
expiration.
Stop nopin timer before stopping the nopin response timer to be sure
that no one of them will be re-started. |
| In the Linux kernel, the following vulnerability has been resolved:
nvmet-tcp: don't restore null sk_state_change
queue->state_change is set as part of nvmet_tcp_set_queue_sock(), but if
the TCP connection isn't established when nvmet_tcp_set_queue_sock() is
called then queue->state_change isn't set and sock->sk->sk_state_change
isn't replaced.
As such we don't need to restore sock->sk->sk_state_change if
queue->state_change is NULL.
This avoids NULL pointer dereferences such as this:
[ 286.462026][ C0] BUG: kernel NULL pointer dereference, address: 0000000000000000
[ 286.462814][ C0] #PF: supervisor instruction fetch in kernel mode
[ 286.463796][ C0] #PF: error_code(0x0010) - not-present page
[ 286.464392][ C0] PGD 8000000140620067 P4D 8000000140620067 PUD 114201067 PMD 0
[ 286.465086][ C0] Oops: Oops: 0010 [#1] SMP KASAN PTI
[ 286.465559][ C0] CPU: 0 UID: 0 PID: 1628 Comm: nvme Not tainted 6.15.0-rc2+ #11 PREEMPT(voluntary)
[ 286.466393][ C0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014
[ 286.467147][ C0] RIP: 0010:0x0
[ 286.467420][ C0] Code: Unable to access opcode bytes at 0xffffffffffffffd6.
[ 286.467977][ C0] RSP: 0018:ffff8883ae008580 EFLAGS: 00010246
[ 286.468425][ C0] RAX: 0000000000000000 RBX: ffff88813fd34100 RCX: ffffffffa386cc43
[ 286.469019][ C0] RDX: 1ffff11027fa68b6 RSI: 0000000000000008 RDI: ffff88813fd34100
[ 286.469545][ C0] RBP: ffff88813fd34160 R08: 0000000000000000 R09: ffffed1027fa682c
[ 286.470072][ C0] R10: ffff88813fd34167 R11: 0000000000000000 R12: ffff88813fd344c3
[ 286.470585][ C0] R13: ffff88813fd34112 R14: ffff88813fd34aec R15: ffff888132cdd268
[ 286.471070][ C0] FS: 00007fe3c04c7d80(0000) GS:ffff88840743f000(0000) knlGS:0000000000000000
[ 286.471644][ C0] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 286.472543][ C0] CR2: ffffffffffffffd6 CR3: 000000012daca000 CR4: 00000000000006f0
[ 286.473500][ C0] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 286.474467][ C0] DR3: 0000000000000000 DR6: 00000000ffff07f0 DR7: 0000000000000400
[ 286.475453][ C0] Call Trace:
[ 286.476102][ C0] <IRQ>
[ 286.476719][ C0] tcp_fin+0x2bb/0x440
[ 286.477429][ C0] tcp_data_queue+0x190f/0x4e60
[ 286.478174][ C0] ? __build_skb_around+0x234/0x330
[ 286.478940][ C0] ? rcu_is_watching+0x11/0xb0
[ 286.479659][ C0] ? __pfx_tcp_data_queue+0x10/0x10
[ 286.480431][ C0] ? tcp_try_undo_loss+0x640/0x6c0
[ 286.481196][ C0] ? seqcount_lockdep_reader_access.constprop.0+0x82/0x90
[ 286.482046][ C0] ? kvm_clock_get_cycles+0x14/0x30
[ 286.482769][ C0] ? ktime_get+0x66/0x150
[ 286.483433][ C0] ? rcu_is_watching+0x11/0xb0
[ 286.484146][ C0] tcp_rcv_established+0x6e4/0x2050
[ 286.484857][ C0] ? rcu_is_watching+0x11/0xb0
[ 286.485523][ C0] ? ipv4_dst_check+0x160/0x2b0
[ 286.486203][ C0] ? __pfx_tcp_rcv_established+0x10/0x10
[ 286.486917][ C0] ? lock_release+0x217/0x2c0
[ 286.487595][ C0] tcp_v4_do_rcv+0x4d6/0x9b0
[ 286.488279][ C0] tcp_v4_rcv+0x2af8/0x3e30
[ 286.488904][ C0] ? raw_local_deliver+0x51b/0xad0
[ 286.489551][ C0] ? rcu_is_watching+0x11/0xb0
[ 286.490198][ C0] ? __pfx_tcp_v4_rcv+0x10/0x10
[ 286.490813][ C0] ? __pfx_raw_local_deliver+0x10/0x10
[ 286.491487][ C0] ? __pfx_nf_confirm+0x10/0x10 [nf_conntrack]
[ 286.492275][ C0] ? rcu_is_watching+0x11/0xb0
[ 286.492900][ C0] ip_protocol_deliver_rcu+0x8f/0x370
[ 286.493579][ C0] ip_local_deliver_finish+0x297/0x420
[ 286.494268][ C0] ip_local_deliver+0x168/0x430
[ 286.494867][ C0] ? __pfx_ip_local_deliver+0x10/0x10
[ 286.495498][ C0] ? __pfx_ip_local_deliver_finish+0x10/0x10
[ 286.496204][ C0] ? ip_rcv_finish_core+0x19a/0x1f20
[ 286.496806][ C0] ? lock_release+0x217/0x2c0
[ 286.497414][ C0] ip_rcv+0x455/0x6e0
[ 286.497945][ C0] ? __pfx_ip_rcv+0x10/0x10
[
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
tracing: Verify event formats that have "%*p.."
The trace event verifier checks the formats of trace events to make sure
that they do not point at memory that is not in the trace event itself or
in data that will never be freed. If an event references data that was
allocated when the event triggered and that same data is freed before the
event is read, then the kernel can crash by reading freed memory.
The verifier runs at boot up (or module load) and scans the print formats
of the events and checks their arguments to make sure that dereferenced
pointers are safe. If the format uses "%*p.." the verifier will ignore it,
and that could be dangerous. Cover this case as well.
Also add to the sample code a use case of "%*pbl". |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: btusb: avoid NULL pointer dereference in skb_dequeue()
A NULL pointer dereference can occur in skb_dequeue() when processing a
QCA firmware crash dump on WCN7851 (0489:e0f3).
[ 93.672166] Bluetooth: hci0: ACL memdump size(589824)
[ 93.672475] BUG: kernel NULL pointer dereference, address: 0000000000000008
[ 93.672517] Workqueue: hci0 hci_devcd_rx [bluetooth]
[ 93.672598] RIP: 0010:skb_dequeue+0x50/0x80
The issue stems from handle_dump_pkt_qca() returning 0 even when a dump
packet is successfully processed. This is because it incorrectly
forwards the return value of hci_devcd_init() (which returns 0 on
success). As a result, the caller (btusb_recv_acl_qca() or
btusb_recv_evt_qca()) assumes the packet was not handled and passes it
to hci_recv_frame(), leading to premature kfree() of the skb.
Later, hci_devcd_rx() attempts to dequeue the same skb from the dump
queue, resulting in a NULL pointer dereference.
Fix this by:
1. Making handle_dump_pkt_qca() return 0 on success and negative errno
on failure, consistent with kernel conventions.
2. Splitting dump packet detection into separate functions for ACL
and event packets for better structure and readability.
This ensures dump packets are properly identified and consumed, avoiding
double handling and preventing NULL pointer access. |
| In the Linux kernel, the following vulnerability has been resolved:
netfs: Only create /proc/fs/netfs with CONFIG_PROC_FS
When testing a special config:
CONFIG_NETFS_SUPPORTS=y
CONFIG_PROC_FS=n
The system crashes with something like:
[ 3.766197] ------------[ cut here ]------------
[ 3.766484] kernel BUG at mm/mempool.c:560!
[ 3.766789] Oops: invalid opcode: 0000 [#1] SMP NOPTI
[ 3.767123] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Tainted: G W
[ 3.767777] Tainted: [W]=WARN
[ 3.767968] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
[ 3.768523] RIP: 0010:mempool_alloc_slab.cold+0x17/0x19
[ 3.768847] Code: 50 fe ff 58 5b 5d 41 5c 41 5d 41 5e 41 5f e9 93 95 13 00
[ 3.769977] RSP: 0018:ffffc90000013998 EFLAGS: 00010286
[ 3.770315] RAX: 000000000000002f RBX: ffff888100ba8640 RCX: 0000000000000000
[ 3.770749] RDX: 0000000000000000 RSI: 0000000000000003 RDI: 00000000ffffffff
[ 3.771217] RBP: 0000000000092880 R08: 0000000000000000 R09: ffffc90000013828
[ 3.771664] R10: 0000000000000001 R11: 00000000ffffffea R12: 0000000000092cc0
[ 3.772117] R13: 0000000000000400 R14: ffff8881004b1620 R15: ffffea0004ef7e40
[ 3.772554] FS: 0000000000000000(0000) GS:ffff8881b5f3c000(0000) knlGS:0000000000000000
[ 3.773061] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 3.773443] CR2: ffffffff830901b4 CR3: 0000000004296001 CR4: 0000000000770ef0
[ 3.773884] PKRU: 55555554
[ 3.774058] Call Trace:
[ 3.774232] <TASK>
[ 3.774371] mempool_alloc_noprof+0x6a/0x190
[ 3.774649] ? _printk+0x57/0x80
[ 3.774862] netfs_alloc_request+0x85/0x2ce
[ 3.775147] netfs_readahead+0x28/0x170
[ 3.775395] read_pages+0x6c/0x350
[ 3.775623] ? srso_alias_return_thunk+0x5/0xfbef5
[ 3.775928] page_cache_ra_unbounded+0x1bd/0x2a0
[ 3.776247] filemap_get_pages+0x139/0x970
[ 3.776510] ? srso_alias_return_thunk+0x5/0xfbef5
[ 3.776820] filemap_read+0xf9/0x580
[ 3.777054] ? srso_alias_return_thunk+0x5/0xfbef5
[ 3.777368] ? srso_alias_return_thunk+0x5/0xfbef5
[ 3.777674] ? find_held_lock+0x32/0x90
[ 3.777929] ? netfs_start_io_read+0x19/0x70
[ 3.778221] ? netfs_start_io_read+0x19/0x70
[ 3.778489] ? srso_alias_return_thunk+0x5/0xfbef5
[ 3.778800] ? lock_acquired+0x1e6/0x450
[ 3.779054] ? srso_alias_return_thunk+0x5/0xfbef5
[ 3.779379] netfs_buffered_read_iter+0x57/0x80
[ 3.779670] __kernel_read+0x158/0x2c0
[ 3.779927] bprm_execve+0x300/0x7a0
[ 3.780185] kernel_execve+0x10c/0x140
[ 3.780423] ? __pfx_kernel_init+0x10/0x10
[ 3.780690] kernel_init+0xd5/0x150
[ 3.780910] ret_from_fork+0x2d/0x50
[ 3.781156] ? __pfx_kernel_init+0x10/0x10
[ 3.781414] ret_from_fork_asm+0x1a/0x30
[ 3.781677] </TASK>
[ 3.781823] Modules linked in:
[ 3.782065] ---[ end trace 0000000000000000 ]---
This is caused by the following error path in netfs_init():
if (!proc_mkdir("fs/netfs", NULL))
goto error_proc;
Fix this by adding ifdef in netfs_main(), so that /proc/fs/netfs is only
created with CONFIG_PROC_FS. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: xhci: Fix invalid pointer dereference in Etron workaround
This check is performed before prepare_transfer() and prepare_ring(), so
enqueue can already point at the final link TRB of a segment. And indeed
it will, some 0.4% of times this code is called.
Then enqueue + 1 is an invalid pointer. It will crash the kernel right
away or load some junk which may look like a link TRB and cause the real
link TRB to be replaced with a NOOP. This wouldn't end well.
Use a functionally equivalent test which doesn't dereference the pointer
and always gives correct result.
Something has crashed my machine twice in recent days while playing with
an Etron HC, and a control transfer stress test ran for confirmation has
just crashed it again. The same test passes with this patch applied. |
| In the Linux kernel, the following vulnerability has been resolved:
spi: spi-imx: Add check for spi_imx_setupxfer()
Add check for the return value of spi_imx_setupxfer().
spi_imx->rx and spi_imx->tx function pointer can be NULL when
spi_imx_setupxfer() return error, and make NULL pointer dereference.
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
Call trace:
0x0
spi_imx_pio_transfer+0x50/0xd8
spi_imx_transfer_one+0x18c/0x858
spi_transfer_one_message+0x43c/0x790
__spi_pump_transfer_message+0x238/0x5d4
__spi_sync+0x2b0/0x454
spi_write_then_read+0x11c/0x200 |
| In the Linux kernel, the following vulnerability has been resolved:
driver core: fix potential NULL pointer dereference in dev_uevent()
If userspace reads "uevent" device attribute at the same time as another
threads unbinds the device from its driver, change to dev->driver from a
valid pointer to NULL may result in crash. Fix this by using READ_ONCE()
when fetching the pointer, and take bus' drivers klist lock to make sure
driver instance will not disappear while we access it.
Use WRITE_ONCE() when setting the driver pointer to ensure there is no
tearing. |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: add mutual exclusion in proc_sctp_do_udp_port()
We must serialize calls to sctp_udp_sock_stop() and sctp_udp_sock_start()
or risk a crash as syzbot reported:
Oops: general protection fault, probably for non-canonical address 0xdffffc000000000d: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f]
CPU: 1 UID: 0 PID: 6551 Comm: syz.1.44 Not tainted 6.14.0-syzkaller-g7f2ff7b62617 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:kernel_sock_shutdown+0x47/0x70 net/socket.c:3653
Call Trace:
<TASK>
udp_tunnel_sock_release+0x68/0x80 net/ipv4/udp_tunnel_core.c:181
sctp_udp_sock_stop+0x71/0x160 net/sctp/protocol.c:930
proc_sctp_do_udp_port+0x264/0x450 net/sctp/sysctl.c:553
proc_sys_call_handler+0x3d0/0x5b0 fs/proc/proc_sysctl.c:601
iter_file_splice_write+0x91c/0x1150 fs/splice.c:738
do_splice_from fs/splice.c:935 [inline]
direct_splice_actor+0x18f/0x6c0 fs/splice.c:1158
splice_direct_to_actor+0x342/0xa30 fs/splice.c:1102
do_splice_direct_actor fs/splice.c:1201 [inline]
do_splice_direct+0x174/0x240 fs/splice.c:1227
do_sendfile+0xafd/0xe50 fs/read_write.c:1368
__do_sys_sendfile64 fs/read_write.c:1429 [inline]
__se_sys_sendfile64 fs/read_write.c:1415 [inline]
__x64_sys_sendfile64+0x1d8/0x220 fs/read_write.c:1415
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] |
| In the Linux kernel, the following vulnerability has been resolved:
tracing: Fix bad hist from corrupting named_triggers list
The following commands causes a crash:
~# cd /sys/kernel/tracing/events/rcu/rcu_callback
~# echo 'hist:name=bad:keys=common_pid:onmax(bogus).save(common_pid)' > trigger
bash: echo: write error: Invalid argument
~# echo 'hist:name=bad:keys=common_pid' > trigger
Because the following occurs:
event_trigger_write() {
trigger_process_regex() {
event_hist_trigger_parse() {
data = event_trigger_alloc(..);
event_trigger_register(.., data) {
cmd_ops->reg(.., data, ..) [hist_register_trigger()] {
data->ops->init() [event_hist_trigger_init()] {
save_named_trigger(name, data) {
list_add(&data->named_list, &named_triggers);
}
}
}
}
ret = create_actions(); (return -EINVAL)
if (ret)
goto out_unreg;
[..]
ret = hist_trigger_enable(data, ...) {
list_add_tail_rcu(&data->list, &file->triggers); <<<---- SKIPPED!!! (this is important!)
[..]
out_unreg:
event_hist_unregister(.., data) {
cmd_ops->unreg(.., data, ..) [hist_unregister_trigger()] {
list_for_each_entry(iter, &file->triggers, list) {
if (!hist_trigger_match(data, iter, named_data, false)) <- never matches
continue;
[..]
test = iter;
}
if (test && test->ops->free) <<<-- test is NULL
test->ops->free(test) [event_hist_trigger_free()] {
[..]
if (data->name)
del_named_trigger(data) {
list_del(&data->named_list); <<<<-- NEVER gets removed!
}
}
}
}
[..]
kfree(data); <<<-- frees item but it is still on list
The next time a hist with name is registered, it causes an u-a-f bug and
the kernel can crash.
Move the code around such that if event_trigger_register() succeeds, the
next thing called is hist_trigger_enable() which adds it to the list.
A bunch of actions is called if get_named_trigger_data() returns false.
But that doesn't need to be called after event_trigger_register(), so it
can be moved up, allowing event_trigger_register() to be called just
before hist_trigger_enable() keeping them together and allowing the
file->triggers to be properly populated. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: consider that tail calls invalidate packet pointers
Tail-called programs could execute any of the helpers that invalidate
packet pointers. Hence, conservatively assume that each tail call
invalidates packet pointers.
Making the change in bpf_helper_changes_pkt_data() automatically makes
use of check_cfg() logic that computes 'changes_pkt_data' effect for
global sub-programs, such that the following program could be
rejected:
int tail_call(struct __sk_buff *sk)
{
bpf_tail_call_static(sk, &jmp_table, 0);
return 0;
}
SEC("tc")
int not_safe(struct __sk_buff *sk)
{
int *p = (void *)(long)sk->data;
... make p valid ...
tail_call(sk);
*p = 42; /* this is unsafe */
...
}
The tc_bpf2bpf.c:subprog_tc() needs change: mark it as a function that
can invalidate packet pointers. Otherwise, it can't be freplaced with
tailcall_freplace.c:entry_freplace() that does a tail call. |
| In the Linux kernel, the following vulnerability has been resolved:
cachefiles: Fix NULL pointer dereference in object->file
At present, the object->file has the NULL pointer dereference problem in
ondemand-mode. The root cause is that the allocated fd and object->file
lifetime are inconsistent, and the user-space invocation to anon_fd uses
object->file. Following is the process that triggers the issue:
[write fd] [umount]
cachefiles_ondemand_fd_write_iter
fscache_cookie_state_machine
cachefiles_withdraw_cookie
if (!file) return -ENOBUFS
cachefiles_clean_up_object
cachefiles_unmark_inode_in_use
fput(object->file)
object->file = NULL
// file NULL pointer dereference!
__cachefiles_write(..., file, ...)
Fix this issue by add an additional reference count to the object->file
before write/llseek, and decrement after it finished. |
| In the Linux kernel, the following vulnerability has been resolved:
nfs/blocklayout: Don't attempt unregister for invalid block device
Since commit d869da91cccb ("nfs/blocklayout: Fix premature PR key
unregistration") an unmount of a pNFS SCSI layout-enabled NFS may
dereference a NULL block_device in:
bl_unregister_scsi+0x16/0xe0 [blocklayoutdriver]
bl_free_device+0x70/0x80 [blocklayoutdriver]
bl_free_deviceid_node+0x12/0x30 [blocklayoutdriver]
nfs4_put_deviceid_node+0x60/0xc0 [nfsv4]
nfs4_deviceid_purge_client+0x132/0x190 [nfsv4]
unset_pnfs_layoutdriver+0x59/0x60 [nfsv4]
nfs4_destroy_server+0x36/0x70 [nfsv4]
nfs_free_server+0x23/0xe0 [nfs]
deactivate_locked_super+0x30/0xb0
cleanup_mnt+0xba/0x150
task_work_run+0x59/0x90
syscall_exit_to_user_mode+0x217/0x220
do_syscall_64+0x8e/0x160
This happens because even though we were able to create the
nfs4_deviceid_node, the lookup for the device was unable to attach the
block device to the pnfs_block_dev.
If we never found a block device to register, we can avoid this case with
the PNFS_BDEV_REGISTERED flag. Move the deref behind the test for the
flag. |
