| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
ublk: reset kernel-owned dev_info fields in ublk_ctrl_add_dev()
ublk_ctrl_add_dev() memcpy()s the userspace ublksrv_ctrl_dev_info into
ub->dev_info and then fixes up the fields the driver owns, but misses
->state and ->ublksrv_pid.
A device added with ->state = UBLK_S_DEV_LIVE passes the
"->state != UBLK_S_DEV_DEAD" test that ublk_stop_dev_unlocked() uses as its
proxy for "a disk is attached", while ->ub_disk is still NULL, so DEL_DEV
right after ADD_DEV oopses in del_gendisk(). UBLK_S_DEV_QUIESCED plus
UBLK_F_USER_RECOVERY dies one step earlier, in ublk_force_abort_dev(). A
poisoned ->state also gets START_USER_RECOVERY and the char device
read/write path onto a device that was never started, and wedges START_DEV
at -EEXIST. A poisoned ->ublksrv_pid just makes GET_DEV_INFO report an
unrelated task as the ublk server.
Reset both after the memcpy(), as ublk_detach_disk() does. Userspace only
ever reads these back, so correcting them silently breaks nothing.
ADD_DEV has copied ->state in unsanitized since ublk was merged, but back
then it was harmless: the gendisk was allocated during ADD_DEV, and both
teardown and the START_DEV -EEXIST check keyed off disk_live() rather than
->state. The oops became reachable once the disk allocation moved to
START_DEV and those checks switched to ->state. |
| Race condition, use-after-free in the Graphics component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1. |
| In the Linux kernel, the following vulnerability has been resolved:
can: bcm: fix data race on rx_stamp/rx_ifindex in bcm_rx_handler()
For an rx op subscribed on all interfaces (ifindex == 0), the same op
is registered once in the shared per-netns wildcard filter list, so
bcm_rx_handler() can run concurrently on different CPUs for frames
arriving on different net devices.
op->rx_stamp and op->rx_ifindex were written before bcm_rx_update_lock was
taken, allowing concurrent writers to race each other - including a torn
store of the 64-bit rx_stamp on 32-bit platforms.
Beyond a torn store bcm_send_to_user() must report the timestamp/ifindex
of the very same frame whose content it is delivering. So the assignment
is placed in the same unbroken bcm_rx_update_lock section as the content
comparison.
As a side effect, the RTR-request frame feature (which never reach
bcm_send_to_user()) no longer updates rx_stamp/rx_ifindex, since only
the notification path needs them. |
| In the Linux kernel, the following vulnerability has been resolved:
can: bcm: add missing device refcount for CAN filter removal
sashiko-bot remarked a problem with a concurrent device unregistration
in isotp.c which also is present in the bcm.c code. A former fix for raw.c
commit c275a176e4b6 ("can: raw: add missing refcount for memory leak fix")
introduced a netdevice_tracker which solves the issue for bcm.c too.
bcm_release(), bcm_delete_rx_op() and bcm_notifier() relied on
dev_get_by_index(ifindex) to re-find the device for an rx_op before
unregistering its filter. If a concurrent NETDEV_UNREGISTER has already
unlisted the device from the ifindex table, that lookup fails and
can_rx_unregister() is silently skipped, leaving a stale CAN filter
pointing at the soon-to-be-freed bcm_op/socket.
Hold a netdev_hold()/netdev_put() tracked reference on op->rx_reg_dev
from the moment the rx filter is registered in bcm_rx_setup() until it
is unregistered in bcm_rx_unreg(), and use that reference directly in
bcm_release() and bcm_delete_rx_op() instead of re-looking the device
up by ifindex. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: x86/mmu: Fix use-after-free on vendor module reload
mmu_destroy_caches() destroys pte_list_desc_cache and
mmu_page_header_cache, but leaves both pointers unchanged. The pointers
live in kvm.ko, and therefore survive when a vendor module is unloaded
while kvm.ko remains loaded.
If creation of pte_list_desc_cache fails during a subsequent vendor
module load, its assignment sets pte_list_desc_cache to NULL and the
error path calls mmu_destroy_caches(). mmu_page_header_cache still
points to the cache destroyed during the preceding vendor module
unload. Passing that stale pointer to kmem_cache_destroy() causes a
slab use-after-free.
Reproduce the issue on a v7.1.3 kernel with CONFIG_KASAN=y,
CONFIG_KASAN_GENERIC=y, CONFIG_KVM=m, and CONFIG_KVM_INTEL=m. A
one-shot test hook forces pte_list_desc_cache to NULL on the second
invocation of kvm_mmu_vendor_module_init():
1. Load kvm.ko and kvm-intel.ko, creating both caches.
2. Unload only kvm_intel, leaving kvm.ko loaded.
3. Reload kvm_intel and force initialization through the -ENOMEM path.
KASAN reports:
BUG: KASAN: slab-use-after-free in
kvm_mmu_vendor_module_init+0x5b/0x170 [kvm]
...
kmem_cache_destroy+0x21/0x1d0
kvm_mmu_vendor_module_init+0x5b/0x170 [kvm]
...
Allocated by task 16817:
__kmem_cache_create_args+0x12c/0x3b0
__kmem_cache_create.constprop.0+0xb6/0xf0 [kvm]
kvm_mmu_vendor_module_init+0x13b/0x170 [kvm]
...
Freed by task 16820:
kmem_cache_destroy+0x117/0x1d0
kvm_mmu_vendor_module_exit+0x21/0x30 [kvm]
Clear both pointers immediately after destroying their caches so that
the stored state reflects the caches' lifetime and repeated cleanup is
safe.
With the fix applied, the same injected vendor module reload fails with
-ENOMEM as expected and produces no KASAN report. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: free AP_VLAN bc_buf SKBs outside IRQ lock
ieee80211_do_stop() removes AP_VLAN packets from the parent AP
ps->bc_buf while holding ps->bc_buf.lock with IRQs disabled. It then
calls ieee80211_free_txskb() before dropping the lock.
ieee80211_free_txskb() is not just a passive SKB release. For SKBs with
TX status state it can report a dropped frame through cfg80211/nl80211,
and that path can reach netlink tap transmit. This is the same reason
the pending queue cleanup in ieee80211_do_stop() already unlinks SKBs
under the queue lock and frees them after IRQ state is restored.
The buggy scenario involves two paths, with each column showing the
order within that path:
AP_VLAN management TX: AP_VLAN stop:
1. attach ACK-status state 1. clear the running state
2. queue a multicast SKB on 2. take ps->bc_buf.lock with IRQs
parent ps->bc_buf disabled
3. unlink the AP_VLAN SKB
4. call ieee80211_free_txskb()
Unlink matching AP_VLAN SKBs from ps->bc_buf under the existing lock,
but move them to a local free queue. Drop the lock and restore IRQ state
before calling ieee80211_free_txskb().
WARNING: kernel/softirq.c:430 at __local_bh_enable_ip |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: brcmfmac: initialize SDIO data work before cleanup
brcmf_sdio_probe() stores the newly allocated bus in sdiodev->bus before
allocating the ordered workqueue. If that allocation fails, the function
jumps to fail and calls brcmf_sdio_remove().
brcmf_sdio_remove() unconditionally cancels bus->datawork. Initialize the
work item before the first failure path that can reach brcmf_sdio_remove(),
so the cleanup path always observes a valid work object.
This issue was found by our static analysis tool and then confirmed by
manual review of the probe error path and the remove-time work drain. The
problem pattern is an early setup failure that reaches a cleanup helper
which cancels an embedded work item before its initializer has run.
A QEMU PoC forced alloc_ordered_workqueue() to fail at the same point in
brcmf_sdio_probe(), before INIT_WORK(&bus->datawork) is reached. The
resulting fail path calls brcmf_sdio_remove(), and DEBUG_OBJECTS reports
the invalid work drain with brcmf_sdio_probe() and brcmf_sdio_remove() in
the stack. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: dummy_hcd: prevent fifo_req reuse during giveback
dummy_hcd embeds a single shared usb_request (dum->fifo_req) that the
"emulated single-request FIFO" fast-path in dummy_queue() reuses for
small IN transfers: it copies the caller's request into it
(req->req = *_req) and queues it, treating list_empty(&fifo_req.queue)
as "the slot is free".
The completion side (dummy_timer/transfer/nuke/dummy_dequeue) follows
the standard pattern: list_del_init(&req->queue) unlinks the request,
then the lock is dropped and usb_gadget_giveback_request() invokes
req->complete(). But list_del_init() makes fifo_req.queue look empty
*before* the completion callback returns, so a concurrent dummy_queue()
on another CPU sees the slot as free, reuses fifo_req and runs
req->req = *_req -- overwriting req->complete while dummy_timer is
mid-calling it. The indirect call then jumps to a clobbered pointer,
causing a general protection fault / page fault in dummy_timer
(syzkaller extid faf3a6cf579fc65591ca). The clobbering write is an
in-bounds memcpy on a live shared object, so KASAN cannot flag it.
Add a fifo_req_busy bit covering the shared request's whole lifetime:
set it in dummy_queue() when the FIFO fast-path takes fifo_req (making
it the fast-path guard, replacing the list_empty(&fifo_req.queue)
test), and clear it after the completion callback has returned, via a
dummy_giveback() helper used at all four gadget-request giveback
sites. The shared slot can no longer be reused until its completion
callback has finished. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: ath9k: hif_usb: don't dereference hif_dev after re-arming firmware request
ath9k_hif_request_firmware() re-arms an asynchronous firmware load via
request_firmware_nowait(), passing hif_dev as the completion context, and
then still dereferences hif_dev:
dev_info(&hif_dev->udev->dev, "ath9k_htc: Firmware %s requested\n",
hif_dev->fw_name);
The re-armed callback ath9k_hif_usb_firmware_cb() runs on the "events"
workqueue and, when the firmware is missing, walks the retry chain into
ath9k_hif_usb_firmware_fail() -> complete_all(&hif_dev->fw_done). That
releases the wait_for_completion(&hif_dev->fw_done) in a concurrent
ath9k_hif_usb_disconnect(), which then kfree()s hif_dev. The trailing
dev_info() in the frame that re-armed the request can therefore read freed
memory (hif_dev->udev, the first field of struct hif_device_usb):
BUG: KASAN: slab-use-after-free in ath9k_hif_request_firmware
Read of size 8 ... by task kworker/...
ath9k_hif_request_firmware
ath9k_hif_usb_firmware_cb drivers/net/wireless/ath/ath9k/hif_usb.c:1247
request_firmware_work_func
Allocated by ...:
ath9k_hif_usb_probe drivers/net/wireless/ath/ath9k/hif_usb.c
Freed by ...:
ath9k_hif_usb_disconnect -> kfree drivers/net/wireless/ath/ath9k/hif_usb.c
The fw_done barrier only makes disconnect wait for the firmware chain to
*terminate*; it does not protect the outer ath9k_hif_request_firmware()
frame that re-armed the request and keeps touching hif_dev afterwards.
Drop the post-request dev_info(): it is the only use of hif_dev after the
async request is armed, and it is purely informational (the dev_err() on the
failure path runs only when request_firmware_nowait() did not arm a callback,
so hif_dev is still alive there).
This was first reported by syzbot as a single, non-reproduced crash that was
later auto-obsoleted, and was independently rediscovered by the reFuzz fuzzer,
which produced a C reproducer (USB-gadget connect/disconnect of an ath9k_htc
device whose firmware download fails). The vulnerable code is unchanged and
still present in v7.1-rc6, where the slab-use-after-free reproduces under KASAN
once the (sub-microsecond) race window is widened. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: ath11k: fix NULL pointer dereference in ath11k_hal_srng_access_begin
In ATH11K_QMI_EVENT_FW_READY, ATH11K_FLAG_REGISTERED is set
unconditionally even when ath11k_core_qmi_firmware_ready() fails.
This leaves the driver in an inconsistent state where
initialization is considered complete although the firmware ready
handling did not finish successfully. During the subsequent SSR,
the driver enters the restart path based on this incorrect state
and dereferences uninitialized srng members, resulting in a NULL
pointer dereference.
Call trace:
ath11k_hal_srng_access_begin+0xc/0x60 [ath11k] (P)
ath11k_ce_cleanup_pipes+0x17c/0x180 [ath11k]
ath11k_core_restart+0x40/0x168 [ath11k]
Fix this by:
- skipping firmware_ready if ATH11K_FLAG_REGISTERED is already set
- setting ATH11K_FLAG_REGISTERED only when firmware_ready succeeds
- setting ATH11K_FLAG_QMI_FAIL and aborting the FW_READY handling
on error
Tested-on: WCN6750 hw1.0 AHB WLAN.MSL.2.0.c2-00204-QCAMSLSWPLZ-1 |
| In the Linux kernel, the following vulnerability has been resolved:
hwmon: (corsair-cpro) Stop device IO before calling hid_hw_stop
Calling hid_hw_stop() does not stop the device IO.
This results in a race condition between hid_input_report() and the point
immediately following the execution of hid_device_io_start() within
the driver probe function. If the probe operation fails after "io start"
has been initiated, this race condition will result in a UAF vulnerability.
Fix the problem by calling hid_device_io_stop() before calling
hid_hw_stop(). |
| In the Linux kernel, the following vulnerability has been resolved:
hwmon: (nzxt-smart2) Stop device IO before calling hid_hw_stop
Calling hid_hw_stop() does not stop the device IO.
This results in a race condition between hid_input_report() and the point
immediately following the execution of hid_device_io_start() within
the driver probe function. If the probe operation fails after "io start"
has been initiated, this race condition will result in a UAF vulnerability.
Fix the problem by calling hid_device_io_stop() before calling
hid_hw_stop(). |
| In the Linux kernel, the following vulnerability has been resolved:
watchdog: pretimeout: Fix UAF in watchdog_unregister_governor()
When a watchdog governor is unregistered, it updates existing watchdog
devices that were using this governor by falling back to `default_gov`.
If the governor being unregistered is currently set as `default_gov`,
the `default_gov` is never cleared. This leads to 2 use-after-free
issues:
1. New watchdog devices registered after this point will inherit the
dangling `default_gov`.
2. Existing watchdog devices using the unregistered governor will have
their `wdd->gov` reassigned to the dangling `default_gov`.
Fix the UAF by clearing `default_gov` if it matches the governor being
unregistered. |
| In the Linux kernel, the following vulnerability has been resolved:
amt: re-read skb header pointers after every pull
Several AMT receive and transmit paths cache a pointer into the skb head
(ip_hdr(), ipv6_hdr(), eth_hdr() or the AMT message header) and then call
a helper that can reallocate that head before the cached pointer is used
again. pskb_may_pull(), ip_mc_may_pull(), ipv6_mc_may_pull(),
iptunnel_pull_header(), ip_mc_check_igmp() and ipv6_mc_check_mld() can all
free the old head and move the data, so a pointer taken before the call
dangles afterwards and the later access is a use-after-free of the freed
head.
The affected sites are:
amt_rcv() caches ip_hdr() before amt_parse_type() pulls, then reads
iph->saddr.
amt_dev_xmit() caches ip_hdr()/ipv6_hdr() before ip_mc_check_igmp()/
ipv6_mc_check_mld() and pskb_may_pull(), then reads the group address.
amt_multicast_data_handler() caches eth_hdr() before pskb_may_pull(),
then writes the L2 header.
amt_membership_query_handler() caches the AMT header, the outer and
inner eth_hdr() and ip_hdr() before iptunnel_pull_header() and several
pulls, then reads and writes them.
amt_igmpv3_report_handler() and amt_mldv2_report_handler() cache
ip_hdr()/ipv6_hdr() and the current group record and read the record
count from the report header inside the record loop, across the
*_mc_may_pull() calls.
amt_update_handler() caches ip_hdr() and the AMT membership-update
header before pskb_may_pull(), iptunnel_pull_header(),
ip_mc_check_igmp() and the report handler, then reads iph->daddr and
amtmu->nonce / amtmu->response_mac.
Fix each site by either snapshotting the scalar that is used after the
pull before the first pull runs, or re-deriving the header pointer from
the skb after the last pull that can move the head. Values that are
stable across the pull (source and group address, the response MAC and
nonce, the record count, the outer source MAC) are snapshotted; pointers
that are written through or read repeatedly are re-derived. |
| In the Linux kernel, the following vulnerability has been resolved:
comedi: comedi_parport: deal with premature interrupt
Syzbot reported a general protection fault in
`comedi_get_is_subdevice_running()`, which was called from the interrupt
handler `parport_interrupt()` in the "comedi_parport" driver, but it
does not currently have a C reproducer for the problem. It's
probably due to a premature interrupt for one of two reasons:
1. The driver sets up the interrupt handler before the comedi subdevices
used by the interrupt handler have been allocated, but does not
disable the interrupt in the parallel port's CTRL register first.
2. The driver uses a user-supplied I/O port base address which Syzbot
would have supplied, but it might not be backed by real parallel port
hardware.
Change the initialization order in the driver's comedi "attach" handler
(`parport_attach()`) so that the hardware registers are initialized
before the interrupt handler is requested. This should prevent
premature interrupts occurring for real hardware.
Also add a test to the interrupt handler to ensure the comedi device is
fully attached and return early if it isn't. |
| In the Linux kernel, the following vulnerability has been resolved:
fscrypt: Avoid dynamic allocation in fscrypt_get_devices()
When a blk_crypto_key starts being used or is evicted, fs/crypto/ calls
fscrypt_get_devices() to get the filesystem's list of block devices,
then iterates over them and calls blk_crypto_config_supported(),
blk_crypto_start_using_key(), or blk_crypto_evict_key() on each one.
Currently, the block device pointers are placed in a dynamically
allocated array. This dynamic allocation is problematic because:
- It can fail, especially at the fscrypt_destroy_inline_crypt_key() call
site when it's invoked for inode eviction under direct reclaim.
- fscrypt_destroy_inline_crypt_key() doesn't handle the failure. It
just zeroizes and frees the blk_crypto_key without calling
blk_crypto_evict_key(). That causes a use-after-free.
For now, let's fix this in the straightforward and easily-backportable
way by switching to an on-stack array. Currently the fscrypt
multi-device functionality is used only by f2fs, which has a hardcoded
limit of 8 block devices. An on-stack array works fine for that.
(Of course, this solution won't scale up to large number of block
devices. For that we'd need a different solution, like moving the block
device iteration into the filesystem. Or in the case of btrfs, which
will only support blk-crypto-fallback, we should make it just call
blk-crypto-fallback directly, so the block devices won't be needed.) |
| In the Linux kernel, the following vulnerability has been resolved:
net/x25: fix use-after-free in x25_kill_by_neigh()
x25_kill_by_neigh() walks the global X.25 socket list looking for sockets
attached to a terminating neighbour. x25_list_lock protects list membership
while the lookup is in progress, but it does not pin a socket's lifetime
after the lock is dropped.
The function currently drops x25_list_lock before calling lock_sock(s). A
concurrent close can run x25_release(), remove the same socket from
x25_list, and drop the last socket reference in that window. The neighbour
teardown path can then lock or inspect a freed struct sock/struct x25_sock.
Take sock_hold(s) while x25_list_lock still proves that the list entry is
live, then drop the temporary reference after the socket has been locked,
rechecked, and released. Recheck x25_sk(s)->neighbour after lock_sock(),
because another path may have disconnected the socket before this path
acquired the socket lock. Restart the list walk after each disconnect
because the list lock was dropped and the previous iterator state may no
longer be valid.
A QEMU/KASAN run against origin/master reproduced a slab-use-after-free in
x25_kill_by_neigh(). |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: SVM: Bump asid_generation on CPU online to avoid ASID collision after hotplug
If a vCPU stays scheduled out (or blocked) while the last pCPU it ran
on goes through a hotplug cycle (online->offline->online), and the vCPU
then resumes execution on the same pCPU, then it is possible for it to
run with an ASID that has now been assigned to a different vCPU,
resulting in stale TLB translations being used.
svm_enable_virtualization_cpu() resets asid_generation to 1 and sets
next_asid to max_asid + 1 on every CPU online event, including hotplug
cycles. Because next_asid starts beyond the pool boundary, the first
call to new_asid() after an online event always wraps the pool,
incrementing asid_generation to 2 and assigning ASIDs starting from
min_asid.
Consider two vCPUs from different VMs, vCPU-A pinned to CPU-X holding
asid_generation=2 and ASID=N from before the hotplug event:
1. CPU-X goes offline and back online: asid_generation resets to 1,
next_asid = max_asid + 1.
2. One or more vCPUs migrate to CPU-X and call new_asid(), wrapping
the pool and consuming ASIDs starting from min_asid. Eventually
vCPU-B from a different VM is assigned asid_generation=2, ASID=N
— the same ASID that vCPU-A held before the hotplug.
3. vCPU-A enters pre_svm_run() on CPU-X: current_vmcb->cpu is
unchanged so the migration branch is skipped. Its saved
asid_generation=2 matches sd->asid_generation=2, so the generation
check silently passes and vCPU-A continues running with ASID=N —
the same ASID just freshly assigned to vCPU-B.
Both vCPUs from different VMs now run on CPU-X with the same ASID,
causing them to share NPT TLB entries and producing stale translations.
The collision manifests as a KVM internal error (Suberror: 1, emulation
failure). The NPT page fault reports a faulting GPA far outside the
VM's physical memory range — a sign of stale TLB translations being
used. KVM falls back to instruction emulation, which fails on
FPU/XSave instructions (XRSTOR, STMXCSR) that the emulator does not
implement.
Fix this by incrementing asid_generation instead of resetting it to 1
in svm_enable_virtualization_cpu(). On module load, asid_generation
starts at 0 (memset) and the increment produces 1, identical to the
old behaviour. On subsequent hotplug cycles the generation advances
beyond any value a vCPU previously observed on this CPU, so the
generation check in pre_svm_run() reliably forces new_asid() on every
vCPU after every hotplug cycle. |
| In the Linux kernel, the following vulnerability has been resolved:
xfrm: policy: preallocate inexact bins before xfrm_hash_rebuild reinsert
xfrm_hash_rebuild()'s first loop preallocates the bins/chains the reinsert
loop needs, so the reinsert (after hlist_del_rcu()) cannot allocate or
fail. But its guard is inverted: it skips policies with prefixlen <
threshold and preallocates for the rest.
prefixlen < threshold is exactly when policy_hash_bysel() returns NULL and
the reinsert takes the allocating xfrm_policy_inexact_insert() path. So the
loop preallocates for the exact policies (which never allocate) and skips
the inexact ones, whose bin/node is then allocated GFP_ATOMIC during
reinsert. On failure the error path only WARN_ONCE()s and continues,
leaving a poisoned bydst node; the next rebuild's hlist_del_rcu()
dereferences LIST_POISON2 and takes a GPF. Reachable under memory pressure,
deterministic via failslab.
Invert the guard so preallocation covers exactly the reinserted policies;
the reinsert then allocates nothing and cannot fail.
Crash:
Oops: general protection fault, probably for non-canonical address
0xfbd59c0000000024: 0000 [#1] SMP KASAN NOPTI
KASAN: maybe wild-memory-access in range [0xdead...]
...
Workqueue: events xfrm_hash_rebuild
RIP: 0010:xfrm_hash_rebuild+0x5b3/0x1190
RAX: dead000000000122 (LIST_POISON2 + offset)
...
Call Trace:
hlist_del_rcu (include/linux/rculist.h:599)
xfrm_hash_rebuild (net/xfrm/xfrm_policy.c:1365)
process_one_work (kernel/workqueue.c:3322)
worker_thread (kernel/workqueue.c:3486)
kthread (kernel/kthread.c:436)
ret_from_fork (arch/x86/kernel/process.c:158)
ret_from_fork_asm (arch/x86/entry/entry_64.S:245)
...
Kernel panic - not syncing: Fatal exception in interrupt |
| In the Linux kernel, the following vulnerability has been resolved:
ipv4: fib: free fib_alias with kfree_rcu() on insert error path
fib_table_insert() publishes new_fa into the leaf's fa_list with
fib_insert_alias() before calling the fib entry notifiers. When a
notifier fails, the error path removes new_fa with fib_remove_alias()
(hlist_del_rcu) and frees it right away with kmem_cache_free().
fib_table_lookup() walks that list under rcu_read_lock() only, so a
concurrent lookup that already reached new_fa keeps reading it after the
free:
BUG: KASAN: slab-use-after-free in fib_table_lookup (net/ipv4/fib_trie.c:1601)
Read of size 1 at addr ffff88810676d4eb by task exploit/297
Call Trace:
fib_table_lookup (net/ipv4/fib_trie.c:1601)
ip_route_output_key_hash_rcu (net/ipv4/route.c:2814)
ip_route_output_key_hash (net/ipv4/route.c:2705)
__ip4_datagram_connect (net/ipv4/datagram.c:49)
udp_connect (net/ipv4/udp.c:2144)
__sys_connect (net/socket.c:2167)
__x64_sys_connect (net/socket.c:2173)
do_syscall_64
entry_SYSCALL_64_after_hwframe
which belongs to the cache ip_fib_alias of size 56
Triggering the error path needs CAP_NET_ADMIN and a registered fib
notifier that can reject a route; a netdevsim device whose IPv4 FIB
resource is exhausted is enough.
Free new_fa with alias_free_mem_rcu(), as fib_table_delete() already
does for a fib_alias removed from the trie. |
