| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Disable preemption in bpf_perf_event_output
The nesting protection in bpf_perf_event_output relies on disabled
preemption, which is guaranteed for kprobes and tracepoints.
However bpf_perf_event_output can be also called from uprobes context
through bpf_prog_run_array_sleepable function which disables migration,
but keeps preemption enabled.
This can cause task to be preempted by another one inside the nesting
protection and lead eventually to two tasks using same perf_sample_data
buffer and cause crashes like:
kernel tried to execute NX-protected page - exploit attempt? (uid: 0)
BUG: unable to handle page fault for address: ffffffff82be3eea
...
Call Trace:
? __die+0x1f/0x70
? page_fault_oops+0x176/0x4d0
? exc_page_fault+0x132/0x230
? asm_exc_page_fault+0x22/0x30
? perf_output_sample+0x12b/0x910
? perf_event_output+0xd0/0x1d0
? bpf_perf_event_output+0x162/0x1d0
? bpf_prog_c6271286d9a4c938_krava1+0x76/0x87
? __uprobe_perf_func+0x12b/0x540
? uprobe_dispatcher+0x2c4/0x430
? uprobe_notify_resume+0x2da/0xce0
? atomic_notifier_call_chain+0x7b/0x110
? exit_to_user_mode_prepare+0x13e/0x290
? irqentry_exit_to_user_mode+0x5/0x30
? asm_exc_int3+0x35/0x40
Fixing this by disabling preemption in bpf_perf_event_output. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/irdma: Fix data race on CQP completion stats
CQP completion statistics is read lockesly in irdma_wait_event and
irdma_check_cqp_progress while it can be updated in the completion
thread irdma_sc_ccq_get_cqe_info on another CPU as KCSAN reports.
Make completion statistics an atomic variable to reflect coherent updates
to it. This will also avoid load/store tearing logic bug potentially
possible by compiler optimizations.
[77346.170861] BUG: KCSAN: data-race in irdma_handle_cqp_op [irdma] / irdma_sc_ccq_get_cqe_info [irdma]
[77346.171383] write to 0xffff8a3250b108e0 of 8 bytes by task 9544 on cpu 4:
[77346.171483] irdma_sc_ccq_get_cqe_info+0x27a/0x370 [irdma]
[77346.171658] irdma_cqp_ce_handler+0x164/0x270 [irdma]
[77346.171835] cqp_compl_worker+0x1b/0x20 [irdma]
[77346.172009] process_one_work+0x4d1/0xa40
[77346.172024] worker_thread+0x319/0x700
[77346.172037] kthread+0x180/0x1b0
[77346.172054] ret_from_fork+0x22/0x30
[77346.172136] read to 0xffff8a3250b108e0 of 8 bytes by task 9838 on cpu 2:
[77346.172234] irdma_handle_cqp_op+0xf4/0x4b0 [irdma]
[77346.172413] irdma_cqp_aeq_cmd+0x75/0xa0 [irdma]
[77346.172592] irdma_create_aeq+0x390/0x45a [irdma]
[77346.172769] irdma_rt_init_hw.cold+0x212/0x85d [irdma]
[77346.172944] irdma_probe+0x54f/0x620 [irdma]
[77346.173122] auxiliary_bus_probe+0x66/0xa0
[77346.173137] really_probe+0x140/0x540
[77346.173154] __driver_probe_device+0xc7/0x220
[77346.173173] driver_probe_device+0x5f/0x140
[77346.173190] __driver_attach+0xf0/0x2c0
[77346.173208] bus_for_each_dev+0xa8/0xf0
[77346.173225] driver_attach+0x29/0x30
[77346.173240] bus_add_driver+0x29c/0x2f0
[77346.173255] driver_register+0x10f/0x1a0
[77346.173272] __auxiliary_driver_register+0xbc/0x140
[77346.173287] irdma_init_module+0x55/0x1000 [irdma]
[77346.173460] do_one_initcall+0x7d/0x410
[77346.173475] do_init_module+0x81/0x2c0
[77346.173491] load_module+0x1232/0x12c0
[77346.173506] __do_sys_finit_module+0x101/0x180
[77346.173522] __x64_sys_finit_module+0x3c/0x50
[77346.173538] do_syscall_64+0x39/0x90
[77346.173553] entry_SYSCALL_64_after_hwframe+0x63/0xcd
[77346.173634] value changed: 0x0000000000000094 -> 0x0000000000000095 |
| In the Linux kernel, the following vulnerability has been resolved:
serial: 8250_bcm7271: fix leak in `brcmuart_probe`
Smatch reports:
drivers/tty/serial/8250/8250_bcm7271.c:1120 brcmuart_probe() warn:
'baud_mux_clk' from clk_prepare_enable() not released on lines: 1032.
The issue is fixed by using a managed clock. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: typec: bus: verify partner exists in typec_altmode_attention
Some usb hubs will negotiate DisplayPort Alt mode with the device
but will then negotiate a data role swap after entering the alt
mode. The data role swap causes the device to unregister all alt
modes, however the usb hub will still send Attention messages
even after failing to reregister the Alt Mode. type_altmode_attention
currently does not verify whether or not a device's altmode partner
exists, which results in a NULL pointer error when dereferencing
the typec_altmode and typec_altmode_ops belonging to the altmode
partner.
Verify the presence of a device's altmode partner before sending
the Attention message to the Alt Mode driver. |
| In the Linux kernel, the following vulnerability has been resolved:
thermal: intel: quark_dts: fix error pointer dereference
If alloc_soc_dts() fails, then we can just return. Trying to free
"soc_dts" will lead to an Oops. |
| In the Linux kernel, the following vulnerability has been resolved:
mtd: spi-nor: Fix shift-out-of-bounds in spi_nor_set_erase_type
spi_nor_set_erase_type() was used either to set or to mask out an erase
type. When we used it to mask out an erase type a shift-out-of-bounds
was hit:
UBSAN: shift-out-of-bounds in drivers/mtd/spi-nor/core.c:2237:24
shift exponent 4294967295 is too large for 32-bit type 'int'
The setting of the size_{shift, mask} and of the opcode are unnecessary
when the erase size is zero, as throughout the code just the erase size
is considered to determine whether an erase type is supported or not.
Setting the opcode to 0xFF was wrong too as nobody guarantees that 0xFF
is an unused opcode. Thus when masking out an erase type, just set the
erase size to zero. This will fix the shift-out-of-bounds.
[ta: refine changes, new commit message, fix compilation error] |
| In the Linux kernel, the following vulnerability has been resolved:
9p/trans_fd: p9_fd_request: kick rx thread if EPOLLIN
p9_read_work() doesn't set Rworksched and doesn't do schedule_work(m->rq)
if list_empty(&m->req_list).
However, if the pipe is full, we need to read more data and this used to
work prior to commit aaec5a95d59615 ("pipe_read: don't wake up the writer
if the pipe is still full").
p9_read_work() does p9_fd_read() -> ... -> anon_pipe_read() which (before
the commit above) triggered the unnecessary wakeup. This wakeup calls
p9_pollwake() which kicks p9_poll_workfn() -> p9_poll_mux(), p9_poll_mux()
will notice EPOLLIN and schedule_work(&m->rq).
This no longer happens after the optimization above, change p9_fd_request()
to use p9_poll_mux() instead of only checking for EPOLLOUT. |
| In the Linux kernel, the following vulnerability has been resolved:
NFSD: Define actions for the new time_deleg FATTR4 attributes
NFSv4 clients won't send legitimate GETATTR requests for these new
attributes because they are intended to be used only with CB_GETATTR
and SETATTR. But NFSD has to do something besides crashing if it
ever sees a GETATTR request that queries these attributes.
RFC 8881 Section 18.7.3 states:
> The server MUST return a value for each attribute that the client
> requests if the attribute is supported by the server for the
> target file system. If the server does not support a particular
> attribute on the target file system, then it MUST NOT return the
> attribute value and MUST NOT set the attribute bit in the result
> bitmap. The server MUST return an error if it supports an
> attribute on the target but cannot obtain its value. In that case,
> no attribute values will be returned.
Further, RFC 9754 Section 5 states:
> These new attributes are invalid to be used with GETATTR, VERIFY,
> and NVERIFY, and they can only be used with CB_GETATTR and SETATTR
> by a client holding an appropriate delegation.
Thus there does not appear to be a specific server response mandated
by specification. Taking the guidance that querying these attributes
via GETATTR is "invalid", NFSD will return nfserr_inval, failing the
request entirely. |
| In the Linux kernel, the following vulnerability has been resolved:
md/raid10: fix memleak of md thread
In raid10_run(), if setup_conf() succeed and raid10_run() failed before
setting 'mddev->thread', then in the error path 'conf->thread' is not
freed.
Fix the problem by setting 'mddev->thread' right after setup_conf(). |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/irdma: Fix data race on CQP request done
KCSAN detects a data race on cqp_request->request_done memory location
which is accessed locklessly in irdma_handle_cqp_op while being
updated in irdma_cqp_ce_handler.
Annotate lockless intent with READ_ONCE/WRITE_ONCE to avoid any
compiler optimizations like load fusing and/or KCSAN warning.
[222808.417128] BUG: KCSAN: data-race in irdma_cqp_ce_handler [irdma] / irdma_wait_event [irdma]
[222808.417532] write to 0xffff8e44107019dc of 1 bytes by task 29658 on cpu 5:
[222808.417610] irdma_cqp_ce_handler+0x21e/0x270 [irdma]
[222808.417725] cqp_compl_worker+0x1b/0x20 [irdma]
[222808.417827] process_one_work+0x4d1/0xa40
[222808.417835] worker_thread+0x319/0x700
[222808.417842] kthread+0x180/0x1b0
[222808.417852] ret_from_fork+0x22/0x30
[222808.417918] read to 0xffff8e44107019dc of 1 bytes by task 29688 on cpu 1:
[222808.417995] irdma_wait_event+0x1e2/0x2c0 [irdma]
[222808.418099] irdma_handle_cqp_op+0xae/0x170 [irdma]
[222808.418202] irdma_cqp_cq_destroy_cmd+0x70/0x90 [irdma]
[222808.418308] irdma_puda_dele_rsrc+0x46d/0x4d0 [irdma]
[222808.418411] irdma_rt_deinit_hw+0x179/0x1d0 [irdma]
[222808.418514] irdma_ib_dealloc_device+0x11/0x40 [irdma]
[222808.418618] ib_dealloc_device+0x2a/0x120 [ib_core]
[222808.418823] __ib_unregister_device+0xde/0x100 [ib_core]
[222808.418981] ib_unregister_device+0x22/0x40 [ib_core]
[222808.419142] irdma_ib_unregister_device+0x70/0x90 [irdma]
[222808.419248] i40iw_close+0x6f/0xc0 [irdma]
[222808.419352] i40e_client_device_unregister+0x14a/0x180 [i40e]
[222808.419450] i40iw_remove+0x21/0x30 [irdma]
[222808.419554] auxiliary_bus_remove+0x31/0x50
[222808.419563] device_remove+0x69/0xb0
[222808.419572] device_release_driver_internal+0x293/0x360
[222808.419582] driver_detach+0x7c/0xf0
[222808.419592] bus_remove_driver+0x8c/0x150
[222808.419600] driver_unregister+0x45/0x70
[222808.419610] auxiliary_driver_unregister+0x16/0x30
[222808.419618] irdma_exit_module+0x18/0x1e [irdma]
[222808.419733] __do_sys_delete_module.constprop.0+0x1e2/0x310
[222808.419745] __x64_sys_delete_module+0x1b/0x30
[222808.419755] do_syscall_64+0x39/0x90
[222808.419763] entry_SYSCALL_64_after_hwframe+0x63/0xcd
[222808.419829] value changed: 0x01 -> 0x03 |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: qedf: Fix NULL dereference in error handling
Smatch reported:
drivers/scsi/qedf/qedf_main.c:3056 qedf_alloc_global_queues()
warn: missing unwind goto?
At this point in the function, nothing has been allocated so we can return
directly. In particular the "qedf->global_queues" have not been allocated
so calling qedf_free_global_queues() will lead to a NULL dereference when
we check if (!gl[i]) and "gl" is NULL. |
| In the Linux kernel, the following vulnerability has been resolved:
tty: serial: imx: disable Ageing Timer interrupt request irq
There maybe pending USR interrupt before requesting irq, however
uart_add_one_port has not executed, so there will be kernel panic:
[ 0.795668] Unable to handle kernel NULL pointer dereference at virtual addre
ss 0000000000000080
[ 0.802701] Mem abort info:
[ 0.805367] ESR = 0x0000000096000004
[ 0.808950] EC = 0x25: DABT (current EL), IL = 32 bits
[ 0.814033] SET = 0, FnV = 0
[ 0.816950] EA = 0, S1PTW = 0
[ 0.819950] FSC = 0x04: level 0 translation fault
[ 0.824617] Data abort info:
[ 0.827367] ISV = 0, ISS = 0x00000004
[ 0.831033] CM = 0, WnR = 0
[ 0.833866] [0000000000000080] user address but active_mm is swapper
[ 0.839951] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
[ 0.845953] Modules linked in:
[ 0.848869] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.1.1+g56321e101aca #1
[ 0.855617] Hardware name: Freescale i.MX8MP EVK (DT)
[ 0.860452] pstate: 000000c5 (nzcv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 0.867117] pc : __imx_uart_rxint.constprop.0+0x11c/0x2c0
[ 0.872283] lr : imx_uart_int+0xf8/0x1ec
The issue only happends in the inmate linux when Jailhouse hypervisor
enabled. The test procedure is:
while true; do
jailhouse enable imx8mp.cell
jailhouse cell linux xxxx
sleep 10
jailhouse cell destroy 1
jailhouse disable
sleep 5
done
And during the upper test, press keys to the 2nd linux console.
When `jailhouse cell destroy 1`, the 2nd linux has no chance to put
the uart to a quiese state, so USR1/2 may has pending interrupts. Then
when `jailhosue cell linux xx` to start 2nd linux again, the issue
trigger.
In order to disable irqs before requesting them, both UCR1 and UCR2 irqs
should be disabled, so here fix that, disable the Ageing Timer interrupt
in UCR2 as UCR1 does. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: iwlwifi: dvm: Fix memcpy: detected field-spanning write backtrace
A received TKIP key may be up to 32 bytes because it may contain
MIC rx/tx keys too. These are not used by iwl and copying these
over overflows the iwl_keyinfo.key field.
Add a check to not copy more data to iwl_keyinfo.key then will fit.
This fixes backtraces like this one:
memcpy: detected field-spanning write (size 32) of single field "sta_cmd.key.key" at drivers/net/wireless/intel/iwlwifi/dvm/sta.c:1103 (size 16)
WARNING: CPU: 1 PID: 946 at drivers/net/wireless/intel/iwlwifi/dvm/sta.c:1103 iwlagn_send_sta_key+0x375/0x390 [iwldvm]
<snip>
Hardware name: Dell Inc. Latitude E6430/0H3MT5, BIOS A21 05/08/2017
RIP: 0010:iwlagn_send_sta_key+0x375/0x390 [iwldvm]
<snip>
Call Trace:
<TASK>
iwl_set_dynamic_key+0x1f0/0x220 [iwldvm]
iwlagn_mac_set_key+0x1e4/0x280 [iwldvm]
drv_set_key+0xa4/0x1b0 [mac80211]
ieee80211_key_enable_hw_accel+0xa8/0x2d0 [mac80211]
ieee80211_key_replace+0x22d/0x8e0 [mac80211]
<snip> |
| In the Linux kernel, the following vulnerability has been resolved:
media: av7110: prevent underflow in write_ts_to_decoder()
The buf[4] value comes from the user via ts_play(). It is a value in
the u8 range. The final length we pass to av7110_ipack_instant_repack()
is "len - (buf[4] + 1) - 4" so add a check to ensure that the length is
not negative. It's not clear that passing a negative len value does
anything bad necessarily, but it's not best practice.
With the new bounds checking the "if (!len)" condition is no longer
possible or required so remove that. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Address KCSAN report on bpf_lru_list
KCSAN reported a data-race when accessing node->ref.
Although node->ref does not have to be accurate,
take this chance to use a more common READ_ONCE() and WRITE_ONCE()
pattern instead of data_race().
There is an existing bpf_lru_node_is_ref() and bpf_lru_node_set_ref().
This patch also adds bpf_lru_node_clear_ref() to do the
WRITE_ONCE(node->ref, 0) also.
==================================================================
BUG: KCSAN: data-race in __bpf_lru_list_rotate / __htab_lru_percpu_map_update_elem
write to 0xffff888137038deb of 1 bytes by task 11240 on cpu 1:
__bpf_lru_node_move kernel/bpf/bpf_lru_list.c:113 [inline]
__bpf_lru_list_rotate_active kernel/bpf/bpf_lru_list.c:149 [inline]
__bpf_lru_list_rotate+0x1bf/0x750 kernel/bpf/bpf_lru_list.c:240
bpf_lru_list_pop_free_to_local kernel/bpf/bpf_lru_list.c:329 [inline]
bpf_common_lru_pop_free kernel/bpf/bpf_lru_list.c:447 [inline]
bpf_lru_pop_free+0x638/0xe20 kernel/bpf/bpf_lru_list.c:499
prealloc_lru_pop kernel/bpf/hashtab.c:290 [inline]
__htab_lru_percpu_map_update_elem+0xe7/0x820 kernel/bpf/hashtab.c:1316
bpf_percpu_hash_update+0x5e/0x90 kernel/bpf/hashtab.c:2313
bpf_map_update_value+0x2a9/0x370 kernel/bpf/syscall.c:200
generic_map_update_batch+0x3ae/0x4f0 kernel/bpf/syscall.c:1687
bpf_map_do_batch+0x2d9/0x3d0 kernel/bpf/syscall.c:4534
__sys_bpf+0x338/0x810
__do_sys_bpf kernel/bpf/syscall.c:5096 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5094 [inline]
__x64_sys_bpf+0x43/0x50 kernel/bpf/syscall.c:5094
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
read to 0xffff888137038deb of 1 bytes by task 11241 on cpu 0:
bpf_lru_node_set_ref kernel/bpf/bpf_lru_list.h:70 [inline]
__htab_lru_percpu_map_update_elem+0x2f1/0x820 kernel/bpf/hashtab.c:1332
bpf_percpu_hash_update+0x5e/0x90 kernel/bpf/hashtab.c:2313
bpf_map_update_value+0x2a9/0x370 kernel/bpf/syscall.c:200
generic_map_update_batch+0x3ae/0x4f0 kernel/bpf/syscall.c:1687
bpf_map_do_batch+0x2d9/0x3d0 kernel/bpf/syscall.c:4534
__sys_bpf+0x338/0x810
__do_sys_bpf kernel/bpf/syscall.c:5096 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5094 [inline]
__x64_sys_bpf+0x43/0x50 kernel/bpf/syscall.c:5094
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
value changed: 0x01 -> 0x00
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 11241 Comm: syz-executor.3 Not tainted 6.3.0-rc7-syzkaller-00136-g6a66fdd29ea1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023
================================================================== |
| In the Linux kernel, the following vulnerability has been resolved:
media: tuners: qt1010: replace BUG_ON with a regular error
BUG_ON is unnecessary here, and in addition it confuses smatch.
Replacing this with an error return help resolve this smatch
warning:
drivers/media/tuners/qt1010.c:350 qt1010_init() error: buffer overflow 'i2c_data' 34 <= 34 |
| In the Linux kernel, the following vulnerability has been resolved:
MIPS: fw: Allow firmware to pass a empty env
fw_getenv will use env entry to determine style of env,
however it is legal for firmware to just pass a empty list.
Check if first entry exist before running strchr to avoid
null pointer dereference. |
| In the Linux kernel, the following vulnerability has been resolved:
s390/vmem: split pages when debug pagealloc is enabled
Since commit bb1520d581a3 ("s390/mm: start kernel with DAT enabled")
the kernel crashes early during boot when debug pagealloc is enabled:
mem auto-init: stack:off, heap alloc:off, heap free:off
addressing exception: 0005 ilc:2 [#1] SMP DEBUG_PAGEALLOC
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0-rc3-09759-gc5666c912155 #630
[..]
Krnl Code: 00000000001325f6: ec5600248064 cgrj %r5,%r6,8,000000000013263e
00000000001325fc: eb880002000c srlg %r8,%r8,2
#0000000000132602: b2210051 ipte %r5,%r1,%r0,0
>0000000000132606: b90400d1 lgr %r13,%r1
000000000013260a: 41605008 la %r6,8(%r5)
000000000013260e: a7db1000 aghi %r13,4096
0000000000132612: b221006d ipte %r6,%r13,%r0,0
0000000000132616: e3d0d0000171 lay %r13,4096(%r13)
Call Trace:
__kernel_map_pages+0x14e/0x320
__free_pages_ok+0x23a/0x5a8)
free_low_memory_core_early+0x214/0x2c8
memblock_free_all+0x28/0x58
mem_init+0xb6/0x228
mm_core_init+0xb6/0x3b0
start_kernel+0x1d2/0x5a8
startup_continue+0x36/0x40
Kernel panic - not syncing: Fatal exception: panic_on_oops
This is caused by using large mappings on machines with EDAT1/EDAT2. Add
the code to split the mappings into 4k pages if debug pagealloc is enabled
by CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT or the debug_pagealloc kernel
command line option. |
| In the Linux kernel, the following vulnerability has been resolved:
fbdev: udlfb: Fix endpoint check
The syzbot fuzzer detected a problem in the udlfb driver, caused by an
endpoint not having the expected type:
usb 1-1: Read EDID byte 0 failed: -71
usb 1-1: Unable to get valid EDID from device/display
------------[ cut here ]------------
usb 1-1: BOGUS urb xfer, pipe 3 != type 1
WARNING: CPU: 0 PID: 9 at drivers/usb/core/urb.c:504 usb_submit_urb+0xed6/0x1880
drivers/usb/core/urb.c:504
Modules linked in:
CPU: 0 PID: 9 Comm: kworker/0:1 Not tainted
6.4.0-rc1-syzkaller-00016-ga4422ff22142 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google
04/28/2023
Workqueue: usb_hub_wq hub_event
RIP: 0010:usb_submit_urb+0xed6/0x1880 drivers/usb/core/urb.c:504
...
Call Trace:
<TASK>
dlfb_submit_urb+0x92/0x180 drivers/video/fbdev/udlfb.c:1980
dlfb_set_video_mode+0x21f0/0x2950 drivers/video/fbdev/udlfb.c:315
dlfb_ops_set_par+0x2a7/0x8d0 drivers/video/fbdev/udlfb.c:1111
dlfb_usb_probe+0x149a/0x2710 drivers/video/fbdev/udlfb.c:1743
The current approach for this issue failed to catch the problem
because it only checks for the existence of a bulk-OUT endpoint; it
doesn't check whether this endpoint is the one that the driver will
actually use.
We can fix the problem by instead checking that the endpoint used by
the driver does exist and is bulk-OUT. |
| In the Linux kernel, the following vulnerability has been resolved:
nfsd: move init of percpu reply_cache_stats counters back to nfsd_init_net
Commit f5f9d4a314da ("nfsd: move reply cache initialization into nfsd
startup") moved the initialization of the reply cache into nfsd startup,
but didn't account for the stats counters, which can be accessed before
nfsd is ever started. The result can be a NULL pointer dereference when
someone accesses /proc/fs/nfsd/reply_cache_stats while nfsd is still
shut down.
This is a regression and a user-triggerable oops in the right situation:
- non-x86_64 arch
- /proc/fs/nfsd is mounted in the namespace
- nfsd is not started in the namespace
- unprivileged user calls "cat /proc/fs/nfsd/reply_cache_stats"
Although this is easy to trigger on some arches (like aarch64), on
x86_64, calling this_cpu_ptr(NULL) evidently returns a pointer to the
fixed_percpu_data. That struct looks just enough like a newly
initialized percpu var to allow nfsd_reply_cache_stats_show to access
it without Oopsing.
Move the initialization of the per-net+per-cpu reply-cache counters
back into nfsd_init_net, while leaving the rest of the reply cache
allocations to be done at nfsd startup time.
Kudos to Eirik who did most of the legwork to track this down. |
