| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
vfio/pci: Release the VGA arbiter client on register_device() failure
The re-order in the Fixes commit below displaced vfio_pci_vga_init() as
the last failure point of what is now vfio_pci_core_register_device()
without introducing an unwind for the VGA arbiter registration.
In current kernels this is mostly benign because vfio_pci_set_decode()
only uses pci_dev state, but the original failure path could leave a
callback with a freed vdev cookie. The stale registration also becomes
unsafe again once the callback follows drvdata to the vfio device.
Add the required VGA unwind callout. |
| In the Linux kernel, the following vulnerability has been resolved:
vfio: prevent infinite loop in vfio_mig_get_next_state() on blocked arc
vfio_mig_get_next_state() walks vfio_from_fsm_table[] one step at a time,
looping to skip optional states the device does not support until
*next_fsm is supported. A blocked transition is encoded as
VFIO_DEVICE_STATE_ERROR, which the trailing return reports as -EINVAL.
The skip loop does not account for the ERROR sentinel.
state_flags_table[ERROR] is ~0U and vfio_from_fsm_table[ERROR][*] is
ERROR, so once *next_fsm becomes ERROR the loop condition stays true and
*next_fsm never changes. The blocked arcs STOP_COPY -> PRE_COPY and
STOP_COPY -> PRE_COPY_P2P map to ERROR yet pass the support check on a
precopy-capable device, causing the loop to spin forever while holding
the driver state mutex. This can result in a soft lockup, and a panic
with softlockup_panic set.
Terminate the skip loop on the ERROR sentinel so a blocked transition
falls through to the existing return and reports -EINVAL. |
| In the Linux kernel, the following vulnerability has been resolved:
vfio: Remove device debugfs before releasing devres
VFIO device debugfs files created with debugfs_create_devm_seqfile()
store a devres allocated debugfs_devm_entry as inode private data.
vfio_unregister_group_dev() currently calls vfio_device_del() before
vfio_device_debugfs_exit(), but device_del() releases devres. This can
leave debugfs entries visible with stale inode private data while
unregister waits for userspace references to drain.
Remove the per-device debugfs tree before vfio_device_del(). The debugfs
view is diagnostic only, so losing it at the start of unregister is
preferable to preserving entries whose backing storage may already have
been released.
Complete the teardown by clearing the per-device debugfs root after
removal. This matches the global debugfs root cleanup and prevents
future users from mistaking a removed dentry for a live debugfs tree
during the remainder of unregister. |
| In the Linux kernel, the following vulnerability has been resolved:
vfio/mlx5: Fix racy bitfields and tighten struct layout
Bitfield operations are not atomic, they use a read-modify-write
pattern, therefore we should be careful not to pack bitfields that
can be concurrently updated into the same storage unit.
This split takes a binary approach: flags that are only modified
pre/post open/close remain bitfields, flags modified from user
action, including actions that reach across to another device (ex.
reset) use dedicated storage units.
Note mlx5_vhca_page_tracker.status is relocated to fill the alignment
hole this split exposes.
Bitfield justifications:
migrate_cap: written only in mlx5vf_cmd_set_migratable() at probe
chunk_mode: written only in mlx5vf_cmd_set_migratable() at probe
mig_state_cap: written only in mlx5vf_cmd_set_migratable() at probe
Dedicated storage units:
mdev_detach: written in the VF attach/detach event notifier
mlx5fv_vf_event() at runtime
log_active: written in mlx5vf_start_page_tracker()/
mlx5vf_stop_page_tracker() during runtime dirty tracking
deferred_reset: written in mlx5vf_state_mutex_unlock()/
mlx5vf_pci_aer_reset_done() during runtime reset handling
is_err: set by tracker error handling and dirty-log polling at runtime
object_changed: set by tracker event handling and cleared by dirty-log
polling at runtime |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: btusb: fix use-after-free on registration failure
Make sure to release the sibling interfaces in case controller
registration fails to avoid use-after-free and double-free when they are
eventually disconnected.
This issue was reported by Sashiko while reviewing a fix for a wakeup
source leak in the btusb probe errors paths. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: btusb: fix use-after-free on marvell probe failure
Make sure to stop any TX URBs submitted during Marvell OOB wakeup
configuration on later probe failures to avoid use-after-free in the
completion callback.
This issue was reported by Sashiko while reviewing a fix for a wakeup
source leak in the btusb probe errors paths. |
| In the Linux kernel, the following vulnerability has been resolved:
binder: fix UAF in binder_thread_release()
When a thread exits, binder_thread_release() walks its transaction stack
to clear the t->from and t->to_proc that correspond with the exiting
thread. However, a process dying in parallel might attempt to kfree some
of these transactions. And if one of them has no associated t->to_proc,
the t->to_proc->inner_lock will not be acquired.
This means that transaction accesses in binder_thread_release() after
t->to_proc has been cleared might race with binder_free_transaction()
and cause a use-after-free error as reported by KASAN:
==================================================================
BUG: KASAN: slab-use-after-free in binder_thread_release+0x5d0/0x798
Write of size 8 at addr ffff000016627500 by task X/715
CPU: 17 UID: 0 PID: 715 Comm: X Not tainted 7.1.0-rc5-00149-g8fde5d1d47f6 #30 PREEMPT
Hardware name: linux,dummy-virt (DT)
Call trace:
binder_thread_release+0x5d0/0x798
binder_ioctl+0x12c0/0x299c
[...]
Allocated by task 717 on cpu 18 at 67.267803s:
__kasan_kmalloc+0xa0/0xbc
__kmalloc_cache_noprof+0x174/0x444
binder_transaction+0x554/0x8150
binder_thread_write+0xa30/0x4354
binder_ioctl+0x20f0/0x299c
[...]
Freed by task 202 on cpu 18 at 90.416221s:
__kasan_slab_free+0x58/0x80
kfree+0x1a0/0x4a4
binder_free_transaction+0x150/0x294
binder_send_failed_reply+0x398/0x6d8
binder_release_work+0x3e4/0x4ec
binder_deferred_func+0xbd8/0x104c
[...]
==================================================================
In order to avoid this, make sure that binder_free_transaction() reads
the t->to_proc under the transaction lock. This will serialize the
transaction release with the accesses in binder_thread_release(). Plus,
it matches the documented locking rules for @to_proc. |
| In the Linux kernel, the following vulnerability has been resolved:
rust_binder: use a u64 stride when cleaning up the offsets array
Allocation's Drop walks the offsets array (binder_size_t = u64 entries),
cleaning up the objects, but it used usize instead of u64 for both the
stride and the per-entry read.
On 64-bit kernels (usize == u64) this is harmless, but on 32-bit kernels
it walks the 8-byte entries in 4-byte steps, iterating an N-entry array
2N times, and reads the always-zero high word as offset 0, cleaning up
the object at offset 0 N extra times. As a result the referenced node or
handle ends up with a lower reference count than it actually has (a
refcount over-decrement), and binder's reference accounting is corrupted;
for example, the owner can be notified of a strong reference release
(BR_RELEASE) even though references still remain.
Change the stride to u64, and read each entry as a u64, narrowing it to
usize with try_into().
On 32-bit ARM, when this over-decrement would drive a count below zero,
the driver's existing refcount guard refuses it and fires:
rust_binder: Failure: refcount underflow! |
| In the Linux kernel, the following vulnerability has been resolved:
rust_binder: clear freeze listener on node removal
Generally userspace is supposed to explicitly clear freeze listeners
before they drop the refcount on the node ref to zero, but there's
nothing forcing that. Currently, in this scenario the freeze listener
remains in the freeze_listeners rbtree and in the remote node's freeze
listener list, even though the ref for which the listener is registered
is gone. This could potentially lead to a memory leak due to a refcount
cycle. Thus, remove the freeze listener in this scenario. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: xhci: Fix sleep in atomic context in xhci_free_streams()
When a USB device with active stream endpoints is disconnected,
xhci_free_streams() is called from the hub_event workqueue to
free the stream resources. It calls xhci_free_stream_info()
while holding xhci->lock with irqs disabled.
xhci_free_stream_info() invokes xhci_free_stream_ctx(), which
calls dma_free_coherent() for large stream context arrays.
dma_free_coherent() can sleep (e.g. via vunmap), triggering
a BUG when called from atomic context.
Call trace:
dma_free_attrs+0x174/0x220
xhci_free_stream_info+0xd0/0x11c
xhci_free_streams+0x278/0x37c
usb_free_streams+0x98/0xc0
usb_unbind_interface+0x1b8/0x2f8
device_release_driver_internal+0x1d4/0x2cc
device_release_driver+0x18/0x28
bus_remove_device+0x160/0x1a4
device_del+0x1ec/0x350
usb_disable_device+0x98/0x214
usb_disconnect+0xf0/0x35c
hub_event+0xab4/0x19ec
process_one_work+0x278/0x63c
Fix this by saving the stream_info pointers and clearing the
ep references under the lock, then calling xhci_free_stream_info()
outside the lock where sleeping is allowed. |
| In the Linux kernel, the following vulnerability has been resolved:
xhci: sideband: fix ring sg table pages leak
xhci_ring_to_sgtable() allocates a temporary pages array and
uses it to build the returned sg_table with
sg_alloc_table_from_pages().
The error paths free the pages array, but the success path
returns the sg_table without freeing it. This leaks the temporary
array every time a sideband client gets an endpoint or event ring
buffer.
Free the pages array after sg_alloc_table_from_pages() succeeds.
The returned sg_table has its own scatterlist entries and does not
depend on the temporary array after construction. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: typec: tcpci_rt1711h: unregister TCPCI port with devres
rt1711h_probe() registers the TCPCI port before requesting the interrupt
and enabling alert interrupts. If either of those later steps fails, the
probe function returns without unregistering the TCPCI port. The explicit
unregister currently only happens from the remove callback.
Register a devres action immediately after tcpci_register_port() succeeds,
so tcpci_unregister_port() runs on later probe failures and on driver
detach. Drop the remove callback to avoid unregistering the same port
twice.
This issue was identified during our ongoing static-analysis research while
reviewing kernel code. |
| In the Linux kernel, the following vulnerability has been resolved:
PCI: altera: Fix resource leaks on probe failure
The chained IRQ handler is set during probe, but is only removed during the
driver remove(). If pci_host_probe() fails, the handler and INTx IRQ
domain remain set even though the devm-managed host bridge storage
containing struct altera_pcie will be released, leaving the handler with
a stale data pointer.
Interrupts are also enabled before pci_host_probe() is called. If probe
fails after that point, the controller interrupt source should be disabled
before the chained handler and INTx domain are removed.
So set the chained handler only after the INTx domain has been created.
Disable controller interrupts during IRQ teardown, and tear the IRQ setup
down if pci_host_probe() fails.
[mani: commit log] |
| In the Linux kernel, the following vulnerability has been resolved:
PCI: mediatek: Fix IRQ domain leak when port fails to enable
When mtk_pcie_enable_port() fails, mtk_pcie_port_free() removes the port
from pcie->ports and frees the port structure. However, the IRQ domains set
up earlier by mtk_pcie_init_irq_domain() are never freed.
Fix this by refactoring mtk_pcie_irq_teardown() into a per-port helper,
mtk_pcie_irq_teardown_port(), and calling it from mtk_pcie_setup() when
mtk_pcie_enable_port() fails. Since the IRQ teardown must only happen in
the probe error path (during resume, child devices may have active MSI
mappings and the NOIRQ context prohibits sleeping locks),
mtk_pcie_enable_port() is changed to return an error code so callers can
distinguish the two paths and act accordingly.
This issue was reported by Sashiko while reviewing the EcoNet EN7528 SoC
support series. |
| In the Linux kernel, the following vulnerability has been resolved:
PCI/IOV: Skip VF Resizable BAR restore on read error
sriov_restore_vf_rebar_state() uses the VF Resizable BAR Control register
to decide how many VF BARs to restore (nbars) and which VF BAR each
iteration addresses (bar_idx). bar_idx indexes into dev->sriov->barsz[],
which has only PCI_SRIOV_NUM_BARS (6) entries.
When a device does not respond, config reads typically return
PCI_ERROR_RESPONSE (~0). Both fields are 3 bits wide, so nbars and bar_idx
both evaluate to 7. The barsz[] access then goes out of bounds. UBSAN
reports this as:
UBSAN: array-index-out-of-bounds in drivers/pci/iov.c:948:51 index 7 is out of range for type 'resource_size_t [6]'
Observed on an NVIDIA RTX PRO 1000 GPU (GB207GLM) that stopped responding
during a failed GC6 power state exit. The subsequent pci_restore_state()
invoked sriov_restore_vf_rebar_state() while config reads returned
0xffffffff, triggering the splat.
Bail out if any VF Resizable BAR Control read returns PCI_ERROR_RESPONSE.
No further VF BARs are touched, which is safe because a config read that
returns PCI_ERROR_RESPONSE indicates the device is unreachable and
restoration is pointless. This mirrors the guard in
pci_restore_rebar_state(). |
| In the Linux kernel, the following vulnerability has been resolved:
virtio_pci: fix vq info pointer lookup via wrong index
Unbinding a virtio balloon device:
echo virtio0 > /sys/bus/virtio/drivers/virtio_balloon/unbind
triggers a NULL pointer dereference. The dmesg says:
BUG: kernel NULL pointer dereference, address: 0000000000000008
[...]
RIP: 0010:__list_del_entry_valid_or_report+0x5/0xf0
Call Trace:
<TASK>
vp_del_vqs+0x121/0x230
remove_common+0x135/0x150
virtballoon_remove+0xee/0x100
virtio_dev_remove+0x3b/0x80
device_release_driver_internal+0x187/0x2c0
unbind_store+0xb9/0xe0
kernfs_fop_write_iter.llvm.11660790530567441834+0xf6/0x180
vfs_write+0x2a9/0x3b0
ksys_write+0x5c/0xd0
do_syscall_64+0x54/0x230
entry_SYSCALL_64_after_hwframe+0x29/0x31
[...]
</TASK>
The virtio_balloon device registers 5 queues (inflate, deflate, stats,
free_page, reporting) but only the first two are unconditional. The
stats, free_page and reporting queues are each conditional on their
respective feature bits. When any of these features are absent, the
corresponding vqs_info entry has name == NULL, creating holes in the
array.
The root cause is an indexing mismatch introduced when vq info storage
was changed to be passed as an argument. vp_find_vqs_msix() and
vp_find_vqs_intx() store the info pointer at vp_dev->vqs[i], where 'i'
is the caller's sparse array index. However, the virtqueue itself gets
vq->index assigned from queue_idx, a dense index that skips NULL
entries. When holes exist, 'i' and queue_idx diverge. Later,
vp_del_vqs() looks up info via vp_dev->vqs[vq->index] using the dense
index into the sparsely-populated array, and hits NULL.
Fix this by storing info at vp_dev->vqs[queue_idx] instead of
vp_dev->vqs[i], so the store index matches the lookup index
(vq->index). Apply the fix to both the MSIX and INTX paths. |
| In the Linux kernel, the following vulnerability has been resolved:
USB: chaoskey: Fix slab-use-after-free in chaoskey_release()
The chaoskey driver has a use-after-free bug in its release routine.
If the user closes the device file after the USB device has been
unplugged, a debugging log statement will try to access the
usb_interface structure after it has been deallocated:
BUG: KASAN: slab-use-after-free in dev_driver_string (drivers/base/core.c:2406)
Read of size 8 at addr ffff888168e8a0b8 by task chaoskey_raw_re/10106
Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl (lib/dump_stack.c:94 lib/dump_stack.c:120)
print_report (mm/kasan/report.c:378 mm/kasan/report.c:482)
kasan_report (mm/kasan/report.c:595)
dev_driver_string (drivers/base/core.c:2406)
__dynamic_dev_dbg (lib/dynamic_debug.c:906)
chaoskey_release (drivers/usb/misc/chaoskey.c:323)
__fput (fs/file_table.c:510)
fput_close_sync (fs/file_table.c:615)
__x64_sys_close (fs/open.c:1507 fs/open.c:1492 fs/open.c:1492)
do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)
The driver's last reference to the interface structure is dropped in
the chaoskey_free() routine, so the code must not use the interface --
even in a debugging statement -- after that routine returns.
(Exception: If we know that another reference is held by someone else,
such as the device core while the disconnect routine runs, there's no
problem. Thanks to Johan Hovold for pointing this out.)
Since the bad access is part of an unimportant debugging statement,
we can fix the problem simply by removing the whole statement. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: misc: usbio: fix disconnect UAF in client teardown
usbio_disconnect() walks usbio->cli_list in reverse and uninitializes each
auxiliary device. auxiliary_device_uninit() drops the device reference, and
for an unbound child that can run usbio_auxdev_release() and free the
containing struct usbio_client.
list_for_each_entry_reverse() advances after the loop body by reading
client->link.prev. If the current client is freed by
auxiliary_device_uninit(), the iterator dereferences freed memory.
Use list_for_each_entry_safe_reverse() so the previous client is
cached before the body can drop the final reference. This preserves
reverse teardown order while keeping the next iterator cursor independent
of the current client's lifetime.
Validation reproduced this kernel report:
BUG: KASAN: slab-use-after-free in usbio_disconnect+0x12e/0x150
Call Trace:
<TASK>
dump_stack_lvl+0x66/0xa0
print_report+0xce/0x630
? usbio_disconnect+0x12e/0x150
? srso_alias_return_thunk+0x5/0xfbef5
? __virt_addr_valid+0x188/0x320
? usbio_disconnect+0x12e/0x150
kasan_report+0xe0/0x110
? usbio_disconnect+0x12e/0x150
usbio_disconnect+0x12e/0x150
usb_unbind_interface+0xf3/0x400
really_probe+0x316/0x660
__driver_probe_device+0x106/0x240
driver_probe_device+0x4a/0x110
__device_attach_driver+0xf1/0x1a0
? __pfx___device_attach_driver+0x10/0x10
bus_for_each_drv+0xf9/0x160
? __pfx_bus_for_each_drv+0x10/0x10
? srso_alias_return_thunk+0x5/0xfbef5
? trace_hardirqs_on+0x18/0x130
? srso_alias_return_thunk+0x5/0xfbef5
? _raw_spin_unlock_irqrestore+0x44/0x60
__device_attach+0x133/0x2a0
? __pfx___device_attach+0x10/0x10
? srso_alias_return_thunk+0x5/0xfbef5
? do_raw_spin_unlock+0x9a/0x100
? srso_alias_return_thunk+0x5/0xfbef5
device_initial_probe+0x55/0x70
bus_probe_device+0x4a/0xd0
device_add+0x9b9/0xc10
? __pfx_device_add+0x10/0x10
? _raw_spin_unlock_irqrestore+0x44/0x60
? srso_alias_return_thunk+0x5/0xfbef5
? lockdep_hardirqs_on_prepare+0xea/0x1a0
? srso_alias_return_thunk+0x5/0xfbef5
? usb_enable_lpm+0x3c/0x260
usb_set_configuration+0xb64/0xf20
usb_generic_driver_probe+0x5f/0x90
usb_probe_device+0x71/0x1b0
really_probe+0x46b/0x660
__driver_probe_device+0x106/0x240
driver_probe_device+0x4a/0x110
__device_attach_driver+0xf1/0x1a0
? __pfx___device_attach_driver+0x10/0x10
bus_for_each_drv+0xf9/0x160
? __pfx_bus_for_each_drv+0x10/0x10
? srso_alias_return_thunk+0x5/0xfbef5
? trace_hardirqs_on+0x18/0x130
? srso_alias_return_thunk+0x5/0xfbef5
? _raw_spin_unlock_irqrestore+0x44/0x60
__device_attach+0x133/0x2a0
? __pfx___device_attach+0x10/0x10
? srso_alias_return_thunk+0x5/0xfbef5
? do_raw_spin_unlock+0x9a/0x100
? srso_alias_return_thunk+0x5/0xfbef5
device_initial_probe+0x55/0x70
bus_probe_device+0x4a/0xd0
device_add+0x9b9/0xc10
? __pfx_device_add+0x10/0x10
? srso_alias_return_thunk+0x5/0xfbef5
? add_device_randomness+0xb7/0xf0
usb_new_device+0x492/0x870
hub_event+0x1b10/0x29c0
? __pfx_hub_event+0x10/0x10
? srso_alias_return_thunk+0x5/0xfbef5
? lock_acquire+0x187/0x300
? process_one_work+0x475/0xb90
? srso_alias_return_thunk+0x5/0xfbef5
? lock_release+0xc8/0x290
? srso_alias_return_thunk+0x5/0xfbef5
process_one_work+0x4d7/0xb90
? __pfx_process_one_work+0x10/0x10
? srso_alias_return_thunk+0x5/0xfbef5
? srso_alias_return_thunk+0x5/0xfbef5
? __list_add_valid_or_report+0x37/0xf0
? __pfx_hub_event+0x10/0x10
? srso_alias_return_thunk+0x5/0xfbef5
worker_thread+0x2d8/0x570
? __pfx_worker_thread+0x10/0x10
kthread+0x1ad/0x1f0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x3c9/0x540
? __pfx_ret_from_fork+0x10/0x10
? srso_alias_return_thunk+0x5/0xfbef5
? __switch_to+0x2e9/0x730
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK> |
| In the Linux kernel, the following vulnerability has been resolved:
6lowpan: fix NHC entry use-after-free on error path
lowpan_nhc_do_uncompression() looks up an NHC descriptor while holding
lowpan_nhc_lock. If the descriptor has no uncompress callback, the error
path drops the lock before printing nhc->name.
lowpan_nhc_del() removes descriptors under the same lock and then relies
on synchronize_net() before the owning module can be unloaded. That only
waits for net RX RCU readers. lowpan_header_decompress() is also exported
and can be reached from callers that are not necessarily covered by the net
core RX critical section, for example the Bluetooth 6LoWPAN L2CAP receive
path.
This leaves a race where one task drops lowpan_nhc_lock in the error path,
another task unregisters and frees the matching descriptor after
synchronize_net() returns, and the first task then dereferences nhc->name
for the warning.
With the post-unlock window widened, KASAN reports:
BUG: KASAN: slab-use-after-free in lowpan_nhc_do_uncompression+0x1f4/0x220
Read of size 8
lowpan_nhc_do_uncompression
lowpan_header_decompress
Fix this by printing the warning before dropping lowpan_nhc_lock, so the
descriptor name is read while unregister is still excluded. The malformed
packet is still rejected with -ENOTSUPP. |
| In the Linux kernel, the following vulnerability has been resolved:
tracing: Fix NULL pointer dereference in func_set_flag()
func_set_flag() dereferences tr->current_trace_flags before verifying
that the current tracer is actually the function tracer. When the active
tracer has been switched away from "function" (e.g., to "wakeup_rt"),
tr->current_trace_flags can be NULL, leading to a NULL pointer
dereference and kernel crash.
The call chain that triggers this is:
trace_options_write()
-> __set_tracer_option()
-> trace->set_flag() /* func_set_flag */
In func_set_flag(), the first operation is:
if (!!set == !!(tr->current_trace_flags->val & bit))
This dereferences tr->current_trace_flags unconditionally. The safety
check that guards against a non-function tracer:
if (tr->current_trace != &function_trace)
return 0;
is placed *after* the dereference, which is too late.
This was observed with the following crash dump:
BUG: unable to handle page fault at 0000000000000000
RIP: func_set_flag+0xd
Call Trace:
__set_tracer_option+0x27
trace_options_write+0x75
vfs_write+0x12a
ksys_write+0x66
do_syscall_64+0x5b
RIP: ffffffff914c973d RSP: ff67ec88b01dfdf0 RFLAGS: 00010202
RAX: 0000000000000000 RBX: ff3a826e80354580 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffffff93918080
The disassembly confirms the fault:
func_set_flag+0: mov 0x1f08(%rdi), %rax ; RAX = tr->current_trace_flags = NULL
func_set_flag+13: mov (%rax), %eax ; page fault: dereference NULL
At the time of the crash:
tr->current_trace_flags = 0x0 (NULL)
tr->current_trace = wakeup_rt_tracer (not function_trace)
The scenario is that a process opens a function tracer option file (such
as "func_stack_trace"), then the current tracer is switched to another
tracer (e.g., "wakeup_rt"), which sets current_trace_flags to NULL. When
the process subsequently writes to the option file, func_set_flag() is
invoked and crashes on the NULL dereference.
Fix this by moving the current_trace check before the
current_trace_flags dereference, so that func_set_flag() returns early
when the function tracer is not active. |
