| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
net/rds: acquire the fastpath locks in rds_conn_shutdown()
rds_conn_shutdown() quiesces the transmit and receive-refill paths by
waiting for RDS_IN_XMIT and RDS_RECV_REFILL to be sampled clear, and
then runs the transport shutdown and rds_conn_path_reset(). Sampling
the bits clear is not the same as owning them: the moment after the
wait_event() returns, rds_send_xmit() can re-acquire RDS_IN_XMIT (or
rds_ib_recv_refill() can re-acquire RDS_RECV_REFILL) and run
concurrently with the teardown.
The sender does recheck the connection state after taking the lock,
but that recheck is a classic store-buffering pattern: teardown writes
the state and reads the bit while the sender writes the bit and reads
the state. acquire_in_xmit() is only an acquire operation, so on
weakly ordered architectures both sides can miss each other's write,
and the transmit path then runs while the transport zeroes its rings
(e.g. rds_ib_ring_init()) and rds_send_path_reset() rewrites the
transmit state under it.
Oracle UEK fixed the same class of crashes - a 14-year tail of
BUG_ON()s in rds_ib_sub_signaled(), unexpected op-codes and NULL
dereferences in rds_ib_send_cqe_handler() during failover testing -
by making the teardown path *acquire* the fastpath bit locks instead
of testing them ("rds: Make sure transmit path and connection
tear-down does not run concurrently"). Ownership of a single word is
decided by RMW atomicity, so no cross-variable ordering is needed.
Do the same here: take both locks before calling the transport
shutdown, hold them across rds_conn_path_reset(), and release them
explicitly with a wake-up afterwards. Both are released with
clear_bit_unlock(), so that the ring re-initialization done by the
transport shutdown and the transmit state rewritten by
rds_send_path_reset() are ordered before either bit is seen clear by
the next acquire_in_xmit() or acquire_refill().
The fastpath users of these bits - rds_send_xmit() and
rds_ib_recv_refill() - are trylock style and back off while teardown
owns the locks, so no new lock dependency is introduced for them.
rds_tcp_reset_callbacks() is different: since the previous patch it
acquires RDS_IN_XMIT as well, and it blocks doing so, so its wait now
spans the teardown instead of at most one send batch. That waiter
runs from rds_tcp_accept_one() on the single-threaded krdsd workqueue
and holds rds_tcp_accept_lock and t_conn_path_lock while it waits, so
a duelling SYN accepted while its path is being torn down parks
accept processing for the duration of the teardown - for TCP bounded
by the (up to 5 s) drain loop in rds_tcp_conn_path_shutdown(). An IB
path's drain in rds_ib_conn_path_shutdown() has no round cap, but no
blocking waiter either: rds_tcp_reset_callbacks() is the only blocking
acquirer of these bits and waits only on its own TCP path, and the
fastpaths are trylock-and-back-off on both transports, so a long IB
drain lengthens only that path's own quiesce. The
window is narrow: the accept-side state check has to pass before the
teardown moves the path to RDS_CONN_DISCONNECTING.
Because krdsd is a single global workqueue, everything else queued
there - accept processing for other connections and network
namespaces, and the flush_workqueue(rds_wq) in rds_tcp_listen_stop()
during namespace teardown - waits behind the parked accept worker for
that time. It cannot deadlock, although the waits do point at each
other: the teardown blocks until the bit's holder releases it, and
the holder may be that krdsd accept worker. The holder finishes
without needing anything the teardown owns: the sync cancels
rds_tcp_reset_callbacks() issues target cp_send_w and cp_recv_w on
the path's ordered cp_wq, whose only execution slot is occupied by
the blocked cp_down_w itself, so they are pending at most and cancel
without flushing - a reliance on cp_wq being ordered that is now
noted next to those cancels (on
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
net/rds: don't let rds_conn_shutdown() consume a concurrent drop
rds_conn_shutdown() finishes by moving the path from
RDS_CONN_DISCONNECTING to RDS_CONN_DOWN, and also accepts
RDS_CONN_ERROR as the starting state of that final transition, so that
a FIN processed in softirq context during the teardown does not derail
the shutdown into a noisy error path.
But consuming that RDS_CONN_ERROR also consumes the shutdown pass that
came with it: rds_conn_path_drop() sets RDS_CONN_ERROR and then queues
cp_down_w, and a pass that starts on a path already in RDS_CONN_DOWN
is a no-op. For the FIN case that is harmless - the socket the FIN
arrived on is the very socket the teardown just released. It is not
harmless for a dropper that attached something to the path first.
rds_tcp_accept_one() is such a dropper. Its path claim in
rds_tcp_accept_one_path() transitions RDS_CONN_DOWN ->
RDS_CONN_CONNECTING, and a concurrent drop - a FIN on a previous
socket in softirq context, an administrative reset - can put the path
into RDS_CONN_ERROR between that claim and the state check that
follows, which accepts RDS_CONN_ERROR. The accept then installs the
freshly accepted socket with rds_tcp_set_callbacks() while the queued
teardown - which sampled tc->t_sock before this socket existed - is
still running. rds_connect_path_complete() fails its transition to
RDS_CONN_UP and drops the path again, queueing the pass that should
reap the socket it just installed. If the in-flight shutdown's final
transition consumes that drop's RDS_CONN_ERROR, the queued pass finds
the path in RDS_CONN_DOWN and does nothing. The installed socket is
never torn down: it sits established with its callbacks armed and its
rds_tcp_connection on rds_tcp_tc_list, the peer sees a connection that
nothing ever reads, and the path is wedged in RDS_CONN_DOWN until some
later event drops it again. Reproduced with widened race windows as
an ever-growing receive queue on a socket owned by a path stuck in
RDS_CONN_DOWN, with the peer's send path wedged behind it.
Make the final transition only DISCONNECTING -> DOWN. If it fails
because the path is in RDS_CONN_ERROR, a drop raced the teardown:
cancel the reconnect timer and clear RDS_RECONNECT_PENDING - the one
piece of the skipped tail that must not be left behind - and return,
letting the pass the drop queued finish the job: it tears down
whatever attached to the path in the meantime, completes the
transition to RDS_CONN_DOWN, and re-arms the reconnect from its own
tail.
The timer quiesce in that branch matters because the racing drop does
not always queue that pass: rds_conn_path_drop() returns without
queueing when a destroy is pending - exactly the situation during a
netns teardown or module unload, when a FIN on the dying socket is
processed while rds_conn_path_destroy() flushes cp_down_w. If the
flushed pass is the one that takes this return, no later pass exists,
and rds_conn_path_destroy() would find cp_conn_w still armed
(WARN_ON) and then free a path whose reconnect timer can still fire.
With the cancel in the branch, every exit of a shutdown pass leaves
the timer quiesced no matter which pass completes the transition.
The FIN case keeps making progress, one pass later and still without
noisy logging. Any other state keeps today's rds_conn_path_error()
handling; no current cp_state writer can leave a DISCONNECTING path
in anything but RDS_CONN_ERROR (every other writer is a cmpxchg from
a non-DISCONNECTING state), so that branch is defensive.
On kernels without the preceding patches the same hazard exists with
the sample-based quiesce; the fix applies there equally. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: caiaq: Fix potential double-free at error path
The fix for caiaq driver's resource management to handle the errors
tries to release the resources in a common destructor call, but as a
sashiko review for another patch suggested, some of the audio
resources such as URBs have been already freed, and this may lead to a
double-free.
For addressing the double-free, call the common destructor function
from each place, and assure that the resource pointers get cleared. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Reject key-less BTF for hash maps
map_check_btf() allows a key-less BTF (btf_key_type_id == 0) only for
maps that have a ->map_check_btf callback, and leaves the actual
decision to that callback. Hash maps used to have no ->map_check_btf,
so a key-less BTF was rejected outright.
That changed when htab and rhtab gained a ->map_check_btf to register a
dtor - htab in commit 1df97a7453ee ("bpf: Register dtor for freeing
special fields") and rhtab in commit 6905f8601298 ("bpf: Allow special
fields in resizable hashtab"). Neither looks at the key, so a key-less
hash map now passes map_check_btf() and gets created. Reading it back
through bpffs feeds the key type_id 0 into btf_type_seq_show();
btf_type_by_id() returns the void type, kind_ops[BTF_KIND_UNKN] is NULL,
and btf_type_show() dereferences it:
RIP: 0010:btf_type_show+0x223/0x2e0 kernel/bpf/btf.c:8232
RSP: 0018:ffffc9000399f868 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000005 RSI: 0000000000000000 RDI: 0000000000000028
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: ffffc9000399f970 R11: 0000000000000001 R12: ffffffff9b96b140
R13: ffffc9000399f8e0 R14: ffff88803d393c00 R15: 0000000000000003
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000000 CR3: 000000003d213000 CR4: 0000000000352ef0
DR0: 0000000039ae8f55 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
btf_type_seq_show_flags+0xca/0x120 kernel/bpf/btf.c:8250
htab_map_seq_show_elem+0x12e/0x350 kernel/bpf/hashtab.c:1669
map_seq_show+0x13d/0x1e0 kernel/bpf/inode.c:293
traverse.part.0.constprop.0+0x107/0x650 fs/seq_file.c:112
traverse fs/seq_file.c:99 [inline]
seq_read_iter+0x93f/0x1270 fs/seq_file.c:196
seq_read+0x344/0x4d0 fs/seq_file.c:163
vfs_read+0x1e4/0xb40 fs/read_write.c:572
ksys_pread64 fs/read_write.c:764 [inline]
__do_sys_pread64 fs/read_write.c:772 [inline]
__se_sys_pread64 fs/read_write.c:769 [inline]
__x64_sys_pread64+0x1eb/0x250 fs/read_write.c:769
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Reject a key-less BTF in htab_map_check_btf() and rhtab_map_check_btf(),
restoring the previous behavior. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix NULL-ptr-deref when showing a void BTF type
btf_modifier_show() resolves the modifier and then calls
btf_type_ops(t)->show() unconditionally. For the void type (type_id 0,
BTF_KIND_UNKN) kind_ops[] has no entry, so ->show is NULL.
A "const void" (a modifier resolving to void) cannot be a map key or
value - map_check_btf() rejects it because void has no size - so the map
dump path does not reach it. But bpf_snprintf_btf() takes a type_id
straight from the BPF program, and passing such a "const void" from the
vmlinux BTF NULL-derefs:
KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
RIP: 0010:btf_modifier_show (kernel/bpf/btf.c:2914)
Call Trace:
<TASK>
btf_type_show (kernel/bpf/btf.c:8251)
btf_type_snprintf_show (kernel/bpf/btf.c:8321)
bpf_snprintf_btf (kernel/trace/bpf_trace.c:1047)
bpf_prog_test_run_raw_tp (net/bpf/test_run.c:829)
__sys_bpf (kernel/bpf/syscall.c:4804)
do_syscall_64 (arch/x86/entry/syscall_64.c:94)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)
</TASK>
Fall back to btf_df_show() when the resolved type has no show op; it
emits the "<unsupported kind:N>" placeholder already used for kinds like
FWD and FUNC. bpf_snprintf_btf() then returns the length as usual. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix NULL-ptr-deref in btf_var_show()
btf_var_show() calls btf_type_id_resolve() unconditionally, which
dereferences btf->resolved_ids. That is NULL for a base BTF - e.g. the
vmlinux BTF that bpf_snprintf_btf() renders against - since base BTF is
not resolved during parsing. btf_modifier_show() guards this with
'if (btf->resolved_ids)', but btf_var_show() does not.
A BPF program that passes the type_id of a BTF_KIND_VAR from the vmlinux
BTF to bpf_snprintf_btf() thus NULL-derefs:
KASAN: probably user-memory-access in range [0x46638-0x4663f]
RIP: 0010:btf_var_show (kernel/bpf/btf.c:2929)
Call Trace:
<TASK>
btf_type_show (kernel/bpf/btf.c:8259)
btf_type_snprintf_show (kernel/bpf/btf.c:8329)
bpf_snprintf_btf (kernel/trace/bpf_trace.c:1047)
bpf_prog_test_run_raw_tp (net/bpf/test_run.c:829)
__sys_bpf (kernel/bpf/syscall.c:4804)
do_syscall_64 (arch/x86/entry/syscall_64.c:84)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)
</TASK>
Resolve the var's type directly with btf_type_skip_modifiers() when
resolved_ids is NULL, mirroring btf_modifier_show(). |
| In the Linux kernel, the following vulnerability has been resolved:
ASoC: Intel: avs: Clean up the bus when fetching ML caps fails
snd_hdac_ext_bus_get_ml_capabilities() may fail and its return code
shall be checked and accounted for. Address the issue by updating the
error-path for avs_pci_probe().
At the same time, if the function in question succeeds but the next part
of avs_pci_probe() fails, the hlink list shall be cleaned up before
leaving the scope. |
| In the Linux kernel, the following vulnerability has been resolved:
net: bcmasp: clear txcb->last before writing each descriptor
bcmasp_xmit() only wrote txcb->last = true for the final fragment
of an SKB; non-final fragments left the field untouched. If a
descriptor slot was reused while it still held a stale true from
a previous SKB (possible when tx_spb_ring_full() underreported
fullness), bcmasp_tx_reclaim() would see last == true mid-SKB and
call dev_consume_skb_any() prematurely, freeing the sk_buff while
its remaining fragments were still in flight.
Unconditionally clear txcb->last before the conditional set so every
descriptor slot starts from a known false state regardless of what a
prior transmission left behind. |
| In the Linux kernel, the following vulnerability has been resolved:
net: bcmasp: fix tx_spb_ring_full() checking same slot cnt times
The loop initialised next_index from intf->tx_spb_index on every
iteration, so incr_ring() always produced the same result and only
one slot was ever tested. Move the initialisation before the loop
so each iteration advances next_index and the function correctly
checks that cnt consecutive descriptor slots are available before
allowing a new transmission. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Mark bpf_btf_find_by_name_kind() as sleepable
When bpf_btf_find_by_name_kind() finds a type in module BTF, it
returns a new BTF object fd through __btf_new_fd(). This reaches
anon_inode_getfd(), which can sleep while allocating or expanding the
current task fd table.
The helper prototype does not set might_sleep, so the verifier allows
the helper in non-sleepable contexts such as BPF timer callbacks. The
fd allocation can then sleep in softirq context and install the fd into
the interrupted task.
Mark the helper as sleepable. This preserves calls from the main body
of a sleepable syscall program while rejecting calls from its
non-sleepable regions. |
| In the Linux kernel, the following vulnerability has been resolved:
nexthop: Initialize extack in remove_nh_grp_entry()
remove_nh_grp_entry() prints the extack message when a listener fails
to replace the reduced nexthop group. However, extack is not
initialized and listeners are not required to set a message when
returning an error. Neither netdevsim nor mlxsw do so when an
allocation fails, resulting in the dereference of an uninitialized
stack pointer.
Fix by zero-initializing extack, as was done in commit 6347c5314cee
("nexthop: initialize extack in nh_res_bucket_migrate()"). |
| In the Linux kernel, the following vulnerability has been resolved:
net: dsa: bcm_sf2: bound the CFP rule dump by the caller's buffer size
bcm_sf2_cfp_rule_get_all() walks the whole cfp.unique bitmap into
rule_locs[] without consulting nfc->rule_cnt, which is how many entries
the caller had room for. ETHTOOL_GRXCLSRLALL requires no CAP_NET_ADMIN
and the ioctl sizes the buffer from the rule_cnt userspace passes in, so
once an admin has installed CFP rules any user can ask for fewer slots
than there are rules and run off the end of the allocation. A rule_cnt
of 0 leaves the buffer pointer NULL and the walk dereferences it. |
| In the Linux kernel, the following vulnerability has been resolved:
net: dsa: mv88e6xxx: bound the policy rule dump by the caller's buffer size
mv88e6xxx_get_rxnfc() uses rxnfc->rule_cnt as the write index while
dumping the policy IDR, clobbering the input value before it has been
looked at. That input is the number of entries the caller had room for.
ETHTOOL_GRXCLSRLALL requires no CAP_NET_ADMIN and the ioctl sizes the
buffer from the rule_cnt userspace passes in, so once an admin has
installed policy rules any user can ask for fewer slots than there are
rules and run off the end of the allocation. A rule_cnt of 0 leaves the
buffer pointer NULL and the walk dereferences it.
Count into a local so the caller's limit survives the walk, and stop with
-EMSGSIZE once it is reached. |
| In the Linux kernel, the following vulnerability has been resolved:
net: bridge: mcast: properly convert mglist to rcu
Sashiko reported a bug [1] that br_multicast_del_port_group unlists the
port group not using proper rcu helper that preserves the next pointer and
after that immediately frees the port group without waiting for rcu grace
period. The only rcu walker of mglist is br_multicast_list_adjacent() and
it turns out that function has always been buggy because mglist was never
properly converted to RCU. Fix it by converting it to rcu and moving its
initialization after eth_addr's. Initializing p->next can use
RCU_INIT_POINTER because we have a barrier from the hlist_add_head_rcu call
later, besides we're initializing an unpublished structure anyway.
[1] https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260826014200.362304-1-littleddfu%40gmail.com |
| In the Linux kernel, the following vulnerability has been resolved:
net: usb: cx82310_eth: drop URB after 0xffff reboot sentinel to prevent partial_data heap overflow
The 0xffff length sentinel detects a router reboot and schedules
re-enabling of ethernet mode, but then falls through to the rest
of the loop body. The next check is
} else if (len > CX82310_MTU) {
which is the else of the just-matched if -- it never fires for
len == 0xffff. The MTU bound that normally caps the
incomplete-packet save path is silently bypassed.
With 0xffff > skb->len always true (rx_urb_size is 4096), the
incomplete-packet branch saves dev->partial_len = skb->len bytes
into dev->partial_data. partial_data is kmalloc(hard_mtu) =
kmalloc(CX82310_MTU + 2) = 1516 bytes, but skb->len after the
2-byte header pull can be up to 4094. A device that sends a
4096-byte URB starting with [0xff 0xff] therefore copies 4094
device-provided bytes into a buffer allocated for 1516 bytes,
exceeding its requested size by 2578 bytes.
The next URB then reads dev->partial_len (4094) back from the same
1516-byte buffer and dev->partial_rem (65535 - 4094 = 61441) from
the new URB's ~4KB skb, both well past their allocations, and
delivers the spliced result as a 64KB "frame" to the network
stack.
Bail out of rx_fixup after scheduling the re-enable work; the
remainder of a reboot-marker URB is not meaningful packet data.
This restores the invariant that partial_len < CX82310_MTU + 2 on
the save path, since every other route there has already passed
the MTU check. |
| In the Linux kernel, the following vulnerability has been resolved:
s390/ism: folio_put() after error
dmb->cpu_addr was allocated via folio_alloc(). Use folio_put() instead of
kfree() in the error exit of ism_alloc_dmb() to avoid slab allocator
corruption.
While at it, reset dmb->cpu_addr after folio_put to avoid unintentional UAF
by future callers. |
| In the Linux kernel, the following vulnerability has been resolved:
vxlan: reject dynamic fdb entries that reference a nexthop id
The commit cited in the Fixes tag allowed VXLAN FDB entries to point to
FDB nexthops so that overlay traffic could be load balanced across
multiple VTEPs. Such entries can only be configured from user space,
cannot be learned and cannot roam. They only make sense with a user space
control plane such as E-VPN where data plane learning is disabled.
Despite that, the VXLAN driver does not currently prevent such entries
from being configured with the "dynamic" flag. The per-nexthop FDB list
is only protected by the per-device hash lock, which is not sufficient
when two VXLAN devices point to the same FDB nexthop and therefore share
the list. Aging runs in softirq context without RTNL, so an entry deleted
by one device can race with an addition or deletion from the other,
leading to list corruption:
list_del corruption. next->prev should be ffff8881069d9548, but was
dead000000000122. (next=ffff8881069d9448)
WARNING: CPU: 0 PID: 90 at lib/list_debug.c:65
__list_del_entry_valid_or_report+0x1aa/0x210
...
vxlan_fdb_destroy+0x5b8/0xad0
vxlan_cleanup+0x328/0x450
call_timer_fn+0x2a/0x1c0
run_timer_softirq+0x18c/0x210
BUG: KASAN: slab-use-after-free in vxlan_fdb_destroy
Fix this by rejecting the bogus configuration of dynamic FDB entries that
point to FDB nexthops, both when created and when an existing entry is
updated. As such, the per-nexthop FDB list is only ever mutated under the
RTNL lock. Add test cases to make sure that this does not regress in the
future. |
| In the Linux kernel, the following vulnerability has been resolved:
net: cap tx_queue_len at S16_MAX to prevent oversized ring allocations
Several subsystems allocate ring buffers sized by dev->tx_queue_len
with no upper bound. An unprivileged user (via unshare -Urn) can set a
huge tx_queue_len and exhaust global memory with ring allocations:
- pfifo_fast: pfifo_fast_init() and pfifo_fast_change_tx_queue_len()
allocate 3 skb_array rings of tx_queue_len entries each.
- tun: tun_queue_resize() and the queue-attach path resize ptr_rings
to tx_queue_len on the NETDEV_CHANGE_TX_QUEUE_LEN notifier.
- tap (macvtap/ipvtap): tap_queue_resize() and tap_init() resize/init
ptr_rings to tx_queue_len on the same notifier.
netif_change_tx_queue_len() is the single entry point for IFLA_TXQLEN,
sysfs, and the SIOCSIFTXQLEN ioctl. Cap new_len at S16_MAX (32767)
there so the oversized value is rejected at set time. This takes
effect whether the device is up or down, before dev->tx_queue_len is
written, before any notifier fires, and before any ring is allocated.
The "> S16_MAX" check also subsumes the previous unsigned-long
truncation test, and a negative ifr_qlen from the ioctl lands far
above the cap after conversion, so both old failure modes are covered
by the one comparison.
tx_queue_len is ambigious: both a per-ring sizing multiplier and a
default queue-length/limit knob for consumers that allocate
nothing at set time (pfifo/bfifo/gred/plug/sfb limits, htb
direct_qlen, qfq max_classes, teql). 32767 is chosen as the largest
value NLA_POLICY_FULL_RANGE can express for the u32 IFLA_TXQLEN
policy in patch 2/3 while staying a legitimate queue length on
high-BDP paths; the ring-memory trade-off of a shared knob is
disclosed below.
Conditions to recreate the bug:
- CONFIG_NET_SCHED=y, CONFIG_VETH=y, CONFIG_USER_NS=y, CONFIG_NET_NS=y.
- Unprivileged user in a fresh user+net namespace (unshare -Urn).
- pfifo_fast: create veth pairs, set tx_queue_len to 500000, attach
mq+pfifo_fast. ~28 iterations OOMs a 2GB guest.
- tun: create 50 tun devices with IFF_MULTI_QUEUE, set tx_queue_len to
500000, open 8 queues each. ~1.6GB of ptr_ring allocations OOMs a
512MB guest.
- tap: same as tun with IFF_TAP. ~960MB OOMs a 512MB guest.
- On the fixed kernel the oversized tx_queue_len is rejected with
-ERANGE at set time (all four paths: RTM_SETLINK, RTM_NEWLINK
create, sysfs, ioctl - the latter two via this check, the former
two via this check and the 2/3 parse policy respectively). |
| In the Linux kernel, the following vulnerability has been resolved:
pds_core: fix cmd_regs access racing BAR unmap on reset
pdsc_reset_prepare() and pdsc_reset_done()'s pdsc_map_bars() error path
clear/iounmap cmd_regs without devcmd_lock, and
pdsc_legacy_firmware_update()'s download loop derefs cmd_regs after
dropping and retaking the lock without re-checking. An FLR concurrent
with a devlink flash can unmap cmd_regs under an in-flight devcmd,
causing a NULL deref or a write to unmapped MMIO.
Take devcmd_lock across the BAR unmap/remap, and re-check cmd_regs in
the download loop. Only the PF maps cmd_regs and runs devcmd, so skip
the unmap on a VF, as pdsc_remove() and pdsc_reset_done() already do.
A reset that completes entirely within the unlocked window is not a
correctness problem for the image: the device clears its update session,
so a resumed download is rejected, and it verifies the staged image
before writing a flash slot, reporting PDS_RC_BAD_FW rather than
activating it.
pdsc_unmap_bars() also clears info_regs, intr_status and intr_ctrl. The
interrupt and start/stop readers of those are quiesced before the unmap
by pdsc_fw_down(), which frees the interrupts and tears down the queues.
The debugfs readers are not, since those files outlive a reset; that is
pre-existing and out of scope here. |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: defer qdisc freeing after failed creation
An RTM_NEWQDISC request can make clsact bind a populated shared ingress
block during ->init(), publishing an embedded mini_Qdisc to lockless
readers. If the same request has an invalid TCA_RATE, estimator setup
fails after ->init(); the unwind removes the pointer but synchronously
frees its containing qdisc while tc_run() may still hold it.
Retire failed qdiscs through the same RCU helper as normal destruction.
Inline the synchronous free into the callback now that no direct callers
remain. |
