| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
slip: bound decode() reads against the compressed packet length
slhc_uncompress() parses a VJ-compressed TCP header by advancing a
pointer through the packet via decode() and pull16(). Neither helper
bounds-checks against isize, and decode() masks its return with
& 0xffff so it can never return the -1 that callers test for -- those
error paths are dead code.
A short compressed frame whose change byte requests optional fields
lets decode() read past the end of the packet. The over-read bytes
are folded into the cached cstate and reflected into subsequent
reconstructed packets.
Make decode() and pull16() take the packet end pointer and return -1
when exhausted. Add a bounds check before the TCP-checksum read.
The existing == -1 tests now do what they were always meant to. |
| In the Linux kernel, the following vulnerability has been resolved:
slip: reject VJ receive packets on instances with no rstate array
slhc_init() accepts rslots == 0 as a valid configuration, with the
documented meaning of 'no receive compression'. In that case the
allocation loop in slhc_init() is skipped, so comp->rstate stays
NULL and comp->rslot_limit stays 0 (from the kzalloc of struct
slcompress).
The receive helpers do not defend against that configuration.
slhc_uncompress() dereferences comp->rstate[x] when the VJ header
carries an explicit connection ID, and slhc_remember() later assigns
cs = &comp->rstate[...] after only comparing the packet's slot number
to comp->rslot_limit. Because rslot_limit is 0, slot 0 passes the
range check, and the code dereferences a NULL rstate.
The configuration is reachable in-tree through PPP. PPPIOCSMAXCID
stores its argument in a signed int, and (val >> 16) uses arithmetic
shift. Passing 0xffff0000 therefore sign-extends to -1, so val2 + 1
is 0 and ppp_generic.c ends up calling slhc_init(0, 1). Because
/dev/ppp open is gated by ns_capable(CAP_NET_ADMIN), the whole path
is reachable from an unprivileged user namespace. Once the malformed
VJ state is installed, any inbound VJ-compressed or VJ-uncompressed
frame that selects slot 0 crashes the kernel in softirq context:
Oops: general protection fault, probably for non-canonical
address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
RIP: 0010:slhc_uncompress (drivers/net/slip/slhc.c:519)
Call Trace:
<TASK>
ppp_receive_nonmp_frame (drivers/net/ppp/ppp_generic.c:2466)
ppp_input (drivers/net/ppp/ppp_generic.c:2359)
ppp_async_process (drivers/net/ppp/ppp_async.c:492)
tasklet_action_common (kernel/softirq.c:926)
handle_softirqs (kernel/softirq.c:623)
run_ksoftirqd (kernel/softirq.c:1055)
smpboot_thread_fn (kernel/smpboot.c:160)
kthread (kernel/kthread.c:436)
ret_from_fork (arch/x86/kernel/process.c:164)
</TASK>
Reject the receive side on such instances instead of touching rstate.
slhc_uncompress() falls through to its existing 'bad' label, which
bumps sls_i_error and enters the toss state. slhc_remember() mirrors
that with an explicit sls_i_error increment followed by slhc_toss();
the sls_i_runt counter is not used here because a missing rstate is
an internal configuration state, not a runt packet.
The transmit path is unaffected: the only in-tree caller that picks
rslots from userspace (ppp_generic.c) still supplies tslots >= 1, and
slip.c always calls slhc_init(16, 16), so comp->tstate remains valid
and slhc_compress() continues to work. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nfnetlink_osf: fix divide-by-zero in OSF_WSS_MODULO
nf_osf_match_one() computes ctx->window % f->wss.val in the
OSF_WSS_MODULO branch with no guard for f->wss.val == 0. A
CAP_NET_ADMIN user can add such a fingerprint via nfnetlink; a
subsequent matching TCP SYN divides by zero and panics the kernel.
Reject the bogus fingerprint in nfnl_osf_add_callback() above the
per-option for-loop. f->wss is per-fingerprint, not per-option, so
the check must run regardless of f->opt_num (including 0). Also
reject wss.wc >= OSF_WSS_MAX; nf_osf_match_one() already treats that
as "should not happen".
Crash:
Oops: divide error: 0000 [#1] SMP KASAN NOPTI
RIP: 0010:nf_osf_match_one (net/netfilter/nfnetlink_osf.c:98)
Call Trace:
<IRQ>
nf_osf_match (net/netfilter/nfnetlink_osf.c:220)
xt_osf_match_packet (net/netfilter/xt_osf.c:32)
ipt_do_table (net/ipv4/netfilter/ip_tables.c:348)
nf_hook_slow (net/netfilter/core.c:622)
ip_local_deliver (net/ipv4/ip_input.c:265)
ip_rcv (include/linux/skbuff.h:1162)
__netif_receive_skb_one_core (net/core/dev.c:6181)
process_backlog (net/core/dev.c:6642)
__napi_poll (net/core/dev.c:7710)
net_rx_action (net/core/dev.c:7945)
handle_softirqs (kernel/softirq.c:622) |
| In the Linux kernel, the following vulnerability has been resolved:
openvswitch: cap upcall PID array size and pre-size vport replies
The vport netlink reply helpers allocate a fixed-size skb with
nlmsg_new(NLMSG_DEFAULT_SIZE, ...) but serialize the full upcall PID
array via ovs_vport_get_upcall_portids(). Since
ovs_vport_set_upcall_portids() accepts any non-zero multiple of
sizeof(u32) with no upper bound, a CAP_NET_ADMIN user can install a PID
array large enough to overflow the reply buffer, causing nla_put() to
fail with -EMSGSIZE and hitting BUG_ON(err < 0). On systems with
unprivileged user namespaces enabled (e.g., Ubuntu default), this is
reachable via unshare -Urn since OVS vport mutation operations use
GENL_UNS_ADMIN_PERM.
kernel BUG at net/openvswitch/datapath.c:2414!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 1 UID: 0 PID: 65 Comm: poc Not tainted 7.0.0-rc7-00195-geb216e422044 #1
RIP: 0010:ovs_vport_cmd_set+0x34c/0x400
Call Trace:
<TASK>
genl_family_rcv_msg_doit (net/netlink/genetlink.c:1116)
genl_rcv_msg (net/netlink/genetlink.c:1194)
netlink_rcv_skb (net/netlink/af_netlink.c:2550)
genl_rcv (net/netlink/genetlink.c:1219)
netlink_unicast (net/netlink/af_netlink.c:1344)
netlink_sendmsg (net/netlink/af_netlink.c:1894)
__sys_sendto (net/socket.c:2206)
__x64_sys_sendto (net/socket.c:2209)
do_syscall_64 (arch/x86/entry/syscall_64.c:63)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
</TASK>
Kernel panic - not syncing: Fatal exception
Reject attempts to set more PIDs than nr_cpu_ids in
ovs_vport_set_upcall_portids(), and pre-compute the worst-case reply
size in ovs_vport_cmd_msg_size() based on that bound, similar to the
existing ovs_dp_cmd_msg_size(). nr_cpu_ids matches the cap already
used by the per-CPU dispatch configuration on the datapath side
(ovs_dp_cmd_fill_info() serialises at most nr_cpu_ids PIDs), so the
two sides stay consistent. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: reject negative CO-RE accessor indices in bpf_core_parse_spec()
CO-RE accessor strings are colon-separated indices that describe a path
from a root BTF type to a target field, e.g. "0:1:2" walks through
nested struct members. bpf_core_parse_spec() parses each component with
sscanf("%d"), so negative values like -1 are silently accepted. The
subsequent bounds checks (access_idx >= btf_vlen(t)) only guard the
upper bound and always pass for negative values because C integer
promotion converts the __u16 btf_vlen result to int, making the
comparison (int)(-1) >= (int)(N) false for any positive N.
When -1 reaches btf_member_bit_offset() it gets cast to u32 0xffffffff,
producing an out-of-bounds read far past the members array. A crafted
BPF program with a negative CO-RE accessor on any struct that exists in
vmlinux BTF (e.g. task_struct) crashes the kernel deterministically
during BPF_PROG_LOAD on any system with CONFIG_DEBUG_INFO_BTF=y
(default on major distributions). The bug is reachable with CAP_BPF:
BUG: unable to handle page fault for address: ffffed11818b6626
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
Oops: Oops: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 85 Comm: poc Not tainted 7.0.0-rc6 #18 PREEMPT(full)
RIP: 0010:bpf_core_parse_spec (tools/lib/bpf/relo_core.c:354)
RAX: 00000000ffffffff
Call Trace:
<TASK>
bpf_core_calc_relo_insn (tools/lib/bpf/relo_core.c:1321)
bpf_core_apply (kernel/bpf/btf.c:9507)
check_core_relo (kernel/bpf/verifier.c:19475)
bpf_check (kernel/bpf/verifier.c:26031)
bpf_prog_load (kernel/bpf/syscall.c:3089)
__sys_bpf (kernel/bpf/syscall.c:6228)
</TASK>
CO-RE accessor indices are inherently non-negative (struct member index,
array element index, or enumerator index), so reject them immediately
after parsing. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: fix end-of-list detection in cgroup_storage_get_next_key()
list_next_entry() never returns NULL -- when the current element is the
last entry it wraps to the list head via container_of(). The subsequent
NULL check is therefore dead code and get_next_key() never returns
-ENOENT for the last element, instead reading storage->key from a bogus
pointer that aliases internal map fields and copying the result to
userspace.
Replace it with list_entry_is_head() so the function correctly returns
-ENOENT when there are no more entries. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: Fix null-ptr-deref in l2cap_sock_get_sndtimeo_cb()
Add the same NULL guard already present in
l2cap_sock_resume_cb() and l2cap_sock_ready_cb(). |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: Fix null-ptr-deref in l2cap_sock_new_connection_cb()
Add the same NULL guard already present in
l2cap_sock_resume_cb() and l2cap_sock_ready_cb(). |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: Fix null-ptr-deref in l2cap_sock_state_change_cb()
Add the same NULL guard already present in
l2cap_sock_resume_cb() and l2cap_sock_ready_cb(). |
| In the Linux kernel, the following vulnerability has been resolved:
net: skbuff: propagate shared-frag marker through frag-transfer helpers
Two frag-transfer helpers (__pskb_copy_fclone() and skb_shift()) fail
to propagate the SKBFL_SHARED_FRAG bit in skb_shinfo()->flags when
moving frags from source to destination. __pskb_copy_fclone() defers
the rest of the shinfo metadata to skb_copy_header() after copying
frag descriptors, but that helper only carries over gso_{size,segs,
type} and never touches skb_shinfo()->flags; skb_shift() moves frag
descriptors directly and leaves flags untouched. As a result, the
destination skb keeps a reference to the same externally-owned or
page-cache-backed pages while reporting skb_has_shared_frag() as
false.
The mismatch is harmful in any in-place writer that uses
skb_has_shared_frag() to decide whether shared pages must be detoured
through skb_cow_data(). ESP input is one such writer (esp4.c,
esp6.c), and a single nft 'dup to <local>' rule -- or any other
nf_dup_ipv4() / xt_TEE caller -- is enough to land a pskb_copy()'d
skb in esp_input() with the marker stripped, letting an unprivileged
user write into the page cache of a root-owned read-only file via
authencesn-ESN stray writes.
Set SKBFL_SHARED_FRAG on the destination whenever frag descriptors
were actually moved from the source. skb_copy() and skb_copy_expand()
share skb_copy_header() too but linearize all paged data into freshly
allocated head storage and emerge with nr_frags == 0, so
skb_has_shared_frag() returns false on its own; they need no change.
The same omission exists in skb_gro_receive() and skb_gro_receive_list().
The former moves the incoming skb's frag descriptors into the
accumulator's last sub-skb via two paths (a direct frag-move loop and
the head_frag + memcpy path); the latter chains the incoming skb whole
onto p's frag_list. Downstream skb_segment() reads only
skb_shinfo(p)->flags, and skb_segment_list() reuses each sub-skb's
shinfo as the nskb -- both p and lp must carry the marker.
The same omission also exists in tcp_clone_payload(), which builds an
MTU probe skb by moving frag descriptors from skbs on sk_write_queue
into a freshly allocated nskb. The helper falls into the same family
and warrants the same fix for consistency; no TCP TX-side in-place
writer is currently known to reach a user page through this gap, but
a future consumer depending on the marker would regress silently.
The same omission exists in skb_segment(): the per-iteration flag
merge takes only head_skb's flag, and the inner switch that rebinds
frag_skb to list_skb on head_skb-frags exhaustion does not fold the
new frag_skb's flag into nskb. Fold frag_skb's flag at both sites
so segments drawing frags from frag_list members carry the marker. |
| In the Linux kernel, the following vulnerability has been resolved:
net/rds: handle zerocopy send cleanup before the message is queued
A zerocopy send can fail after user pages have been pinned but before
the message is attached to the sending socket.
The purge path currently infers zerocopy state from rm->m_rs, so an
unqueued message can be cleaned up as if it owned normal payload pages.
However, zerocopy ownership is really determined by the presence of
op_mmp_znotifier, regardless of whether the message has reached the
socket queue.
Capture op_mmp_znotifier up front in rds_message_purge() and use it as
the cleanup discriminator. If the message is already associated with a
socket, keep the existing completion path. Otherwise, drop the pinned
page accounting directly and release the notifier before putting the
payload pages.
This keeps early send failure cleanup consistent with the zerocopy
lifetime rules without changing the normal queued completion path. |
| In the Linux kernel, the following vulnerability has been resolved:
ipv6: rpl: reserve mac_len headroom when recompressed SRH grows
ipv6_rpl_srh_rcv() decompresses an RFC 6554 Source Routing Header, swaps
the next segment into ipv6_hdr->daddr, recompresses, then pulls the old
header and pushes the new one plus the IPv6 header back. The
recompressed header can be larger than the received one when the swap
reduces the common-prefix length the segments share with daddr (CmprI=0,
CmprE>0, seg[0][0] != daddr[0] gives the maximum +8 bytes).
pskb_expand_head() was gated on segments_left == 0, so on earlier
segments the push consumed unchecked headroom. Once skb_push() leaves
fewer than skb->mac_len bytes in front of data,
skb_mac_header_rebuild()'s call to:
skb_set_mac_header(skb, -skb->mac_len);
will store (data - head) - mac_len into the u16 mac_header field, which
wraps to ~65530, and the following memmove() writes mac_len bytes ~64KiB
past skb->head.
A single AF_INET6/SOCK_RAW/IPV6_HDRINCL packet over lo with a two
segment type-3 SRH (CmprI=0, CmprE=15) reaches headroom 8 after one
pass; KASAN reports a 14-byte OOB write in ipv6_rthdr_rcv.
Fix this by expanding the head whenever the remaining room is less than
the push size plus mac_len, and request that much extra so the rebuilt
MAC header fits afterwards. |
| In the Linux kernel, the following vulnerability has been resolved:
rtmutex: Use waiter::task instead of current in remove_waiter()
remove_waiter() is used by the slowlock paths, but it is also used for
proxy-lock rollback in rt_mutex_start_proxy_lock() when invoked from
futex_requeue().
In the latter case waiter::task is not current, but remove_waiter()
operates on current for the dequeue operation. That results in several
problems:
1) the rbtree dequeue happens without waiter::task::pi_lock being held
2) the waiter task's pi_blocked_on state is not cleared, which leaves a
dangling pointer primed for UAF around.
3) rt_mutex_adjust_prio_chain() operates on the wrong top priority waiter
task
Use waiter::task instead of current in all related operations in
remove_waiter() to cure those problems.
[ tglx: Fixup rt_mutex_adjust_prio_chain(), add a comment and amend the
changelog ] |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: sch_red: Replace direct dequeue call with peek and qdisc_dequeue_peeked
When red qdisc has children (eg qfq qdisc) whose peek() callback is
qdisc_peek_dequeued(), we could get a kernel panic. When the parent of such
qdiscs (eg illustrated in patch #3 as tbf) wants to retrieve an skb from
its child (red in this case), it will do the following:
1a. do a peek() - and when sensing there's an skb the child can offer, then
- the child in this case(red) calls its child's (qfq) peek.
qfq does the right thing and will return the gso_skb queue packet.
Note: if there wasnt a gso_skb entry then qfq will store it there.
1b. invoke a dequeue() on the child (red). And herein lies the problem.
- red will call the child's dequeue() which will essentially just
try to grab something of qfq's queue.
[ 78.667668][ T363] KASAN: null-ptr-deref in range [0x0000000000000048-0x000000000000004f]
[ 78.667927][ T363] CPU: 1 UID: 0 PID: 363 Comm: ping Not tainted 7.1.0-rc1-00033-g46f74a3f7d57-dirty #790 PREEMPT(full)
[ 78.668263][ T363] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 78.668486][ T363] RIP: 0010:qfq_dequeue+0x446/0xc90 [sch_qfq]
[ 78.668718][ T363] Code: 54 c0 e8 dd 90 00 f1 48 c7 c7 e0 03 54 c0 48 89 de e8 ce 90 00 f1 48 8d 7b 48 b8 ff ff 37 00 48 89 fa 48 c1 e0 2a 48 c1 ea 03 <80> 3c 02 00 74 05 e8 ef a1 e1 f1 48 8b 7b 48 48 8d 54 24 58 48 8d
[ 78.669312][ T363] RSP: 0018:ffff88810de573e0 EFLAGS: 00010216
[ 78.669533][ T363] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
[ 78.669790][ T363] RDX: 0000000000000009 RSI: 0000000000000004 RDI: 0000000000000048
[ 78.670044][ T363] RBP: ffff888110dc4000 R08: ffffffffb1b0885a R09: fffffbfff6ba9078
[ 78.670297][ T363] R10: 0000000000000003 R11: ffff888110e31c80 R12: 0000001880000000
[ 78.670560][ T363] R13: ffff888110dc4150 R14: ffff888110dc42b8 R15: 0000000000000200
[ 78.670814][ T363] FS: 00007f66a8f09c40(0000) GS:ffff888163428000(0000) knlGS:0000000000000000
[ 78.671110][ T363] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 78.671324][ T363] CR2: 000055db4c6a30a8 CR3: 000000010da67000 CR4: 0000000000750ef0
[ 78.671585][ T363] PKRU: 55555554
[ 78.671713][ T363] Call Trace:
[ 78.671843][ T363] <TASK>
[ 78.671936][ T363] ? __pfx_qfq_dequeue+0x10/0x10 [sch_qfq]
[ 78.672148][ T363] ? __pfx__printk+0x10/0x10
[ 78.672322][ T363] ? srso_alias_return_thunk+0x5/0xfbef5
[ 78.672496][ T363] ? lockdep_hardirqs_on_prepare+0xa8/0x1a0
[ 78.672706][ T363] ? srso_alias_return_thunk+0x5/0xfbef5
[ 78.672875][ T363] ? trace_hardirqs_on+0x19/0x1a0
[ 78.673047][ T363] red_dequeue+0x65/0x270 [sch_red]
[ 78.673217][ T363] ? srso_alias_return_thunk+0x5/0xfbef5
[ 78.673385][ T363] tbf_dequeue.cold+0xb0/0x70c [sch_tbf]
[ 78.673566][ T363] __qdisc_run+0x169/0x1900
The right thing to do in #1b is to grab the skb off gso_skb queue.
This patchset fixes that issue by changing #1b to use qdisc_dequeue_peeked()
method instead. |
| In the Linux kernel, the following vulnerability has been resolved:
crypto: pcrypt - Fix handling of MAY_BACKLOG requests
MAY_BACKLOG requests can return EBUSY. Handle them by checking
for that value and filtering out EINPROGRESS notifications. |
| In the Linux kernel, the following vulnerability has been resolved:
lib/crypto: mpi: Fix integer underflow in mpi_read_raw_from_sgl()
Yiming reports an integer underflow in mpi_read_raw_from_sgl() when
subtracting "lzeros" from the unsigned "nbytes".
For this to happen, the scatterlist "sgl" needs to occupy more bytes
than the "nbytes" parameter and the first "nbytes + 1" bytes of the
scatterlist must be zero. Under these conditions, the while loop
iterating over the scatterlist will count more zeroes than "nbytes",
subtract the number of zeroes from "nbytes" and cause the underflow.
When commit 2d4d1eea540b ("lib/mpi: Add mpi sgl helpers") originally
introduced the bug, it couldn't be triggered because all callers of
mpi_read_raw_from_sgl() passed a scatterlist whose length was equal to
"nbytes".
However since commit 63ba4d67594a ("KEYS: asymmetric: Use new crypto
interface without scatterlists"), the underflow can now actually be
triggered. When invoking a KEYCTL_PKEY_ENCRYPT system call with a
larger "out_len" than "in_len" and filling the "in" buffer with zeroes,
crypto_akcipher_sync_prep() will create an all-zero scatterlist used for
both the "src" and "dst" member of struct akcipher_request and thereby
fulfil the conditions to trigger the bug:
sys_keyctl()
keyctl_pkey_e_d_s()
asymmetric_key_eds_op()
software_key_eds_op()
crypto_akcipher_sync_encrypt()
crypto_akcipher_sync_prep()
crypto_akcipher_encrypt()
rsa_enc()
mpi_read_raw_from_sgl()
To the user this will be visible as a DoS as the kernel spins forever,
causing soft lockup splats as a side effect.
Fix it. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_ncm: Fix net_device lifecycle with device_move
The network device outlived its parent gadget device during
disconnection, resulting in dangling sysfs links and null pointer
dereference problems.
A prior attempt to solve this by removing SET_NETDEV_DEV entirely [1]
was reverted due to power management ordering concerns and a NO-CARRIER
regression.
A subsequent attempt to defer net_device allocation to bind [2] broke
1:1 mapping between function instance and network device, making it
impossible for configfs to report the resolved interface name. This
results in a regression where the DHCP server fails on pmOS.
Use device_move to reparent the net_device between the gadget device and
/sys/devices/virtual/ across bind/unbind cycles. This preserves the
network interface across USB reconnection, allowing the DHCP server to
retain their binding.
Introduce gether_attach_gadget()/gether_detach_gadget() helpers and use
__free(detach_gadget) macro to undo attachment on bind failure. The
bind_count ensures device_move executes only on the first bind.
[1] https://lore.kernel.org/lkml/f2a4f9847617a0929d62025748384092e5f35cce.camel@crapouillou.net/
[2] https://lore.kernel.org/linux-usb/795ea759-7eaf-4f78-81f4-01ffbf2d7961@ixit.cz/ |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: require a full NFS mode SID before reading mode bits
parse_dacl() treats an ACE SID matching sid_unix_NFS_mode as an NFS
mode SID and reads sid.sub_auth[2] to recover the mode bits.
That assumes the ACE carries three subauthorities, but compare_sids()
only compares min(a, b) subauthorities. A malicious server can return
an ACE with num_subauth = 2 and sub_auth[] = {88, 3}, which still
matches sid_unix_NFS_mode and then drives the sub_auth[2] read four
bytes past the end of the ACE.
Require num_subauth >= 3 before treating the ACE as an NFS mode SID.
This keeps the fix local to the special-SID mode path without changing
compare_sids() semantics for the rest of cifsacl. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/page_alloc: clear page->private in free_pages_prepare()
Several subsystems (slub, shmem, ttm, etc.) use page->private but don't
clear it before freeing pages. When these pages are later allocated as
high-order pages and split via split_page(), tail pages retain stale
page->private values.
This causes a use-after-free in the swap subsystem. The swap code uses
page->private to track swap count continuations, assuming freshly
allocated pages have page->private == 0. When stale values are present,
swap_count_continued() incorrectly assumes the continuation list is valid
and iterates over uninitialized page->lru containing LIST_POISON values,
causing a crash:
KASAN: maybe wild-memory-access in range [0xdead000000000100-0xdead000000000107]
RIP: 0010:__do_sys_swapoff+0x1151/0x1860
Fix this by clearing page->private in free_pages_prepare(), ensuring all
freed pages have clean state regardless of previous use. |
| In the Linux kernel, the following vulnerability has been resolved:
net: Drop the lock in skb_may_tx_timestamp()
skb_may_tx_timestamp() may acquire sock::sk_callback_lock. The lock must
not be taken in IRQ context, only softirq is okay. A few drivers receive
the timestamp via a dedicated interrupt and complete the TX timestamp
from that handler. This will lead to a deadlock if the lock is already
write-locked on the same CPU.
Taking the lock can be avoided. The socket (pointed by the skb) will
remain valid until the skb is released. The ->sk_socket and ->file
member will be set to NULL once the user closes the socket which may
happen before the timestamp arrives.
If we happen to observe the pointer while the socket is closing but
before the pointer is set to NULL then we may use it because both
pointer (and the file's cred member) are RCU freed.
Drop the lock. Use READ_ONCE() to obtain the individual pointer. Add a
matching WRITE_ONCE() where the pointer are cleared. |
