| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
ipv6: exthdrs: refresh nh after handling HAO option
ip6_parse_tlv() caches skb_network_header(skb) in nh while walking
IPv6 TLVs.
ipv6_dest_hao() may call pskb_expand_head() for a cloned skb, which can
move the skb head and invalidate the cached network header pointer.
Refresh nh after ipv6_dest_hao() returns so any trailing padding or TLVs
are parsed from the current skb head.
This matches the existing pattern used in ip6_parse_tlv() after helpers
that can modify skb header storage. |
| In the Linux kernel, the following vulnerability has been resolved:
ip6: vti: Use ip6_tnl.net in vti6_siocdevprivate().
After patch 1/2 in this series, vti6_update() unlinks and relinks
the tunnel through t->net. vti6_siocdevprivate() still uses
dev_net(dev) for the collision lookup. For a tunnel moved through
IFLA_NET_NS_FD, dev_net(dev) is the new netns, not t->net.
SIOCCHGTUNNEL on a migrated tunnel then runs:
net = dev_net(dev) /* migrated netns */
t = vti6_locate(net, &p1, false) /* misses target in t->net */
...
t = netdev_priv(dev)
vti6_update(t, &p1, false) /* mutates t->net's hash */
A caller in the migrated netns picks params that match a tunnel
in the creation netns. The lookup in dev_net(dev) finds nothing.
vti6_update() prepends the migrated tunnel at the head of the
creation netns hash bucket for those params. Later lookups in
the creation netns resolve to the migrated device. xfrm receive
delivers the matched packets through a device the caller controls.
Reachable from an unprivileged user namespace (unshare --user
--map-root-user --net). Cross tenant scope on container hosts.
Switch the SIOCCHGTUNNEL path on a non fallback device to use
t->net for the lookup. The lookup now matches the netns
vti6_update() operates on.
Also add ns_capable(self->net->user_ns, CAP_NET_ADMIN) before
the lookup. The check at the top of the case is against
dev_net(dev)->user_ns, which after migration is the attacker's
netns. A caller there can pick params absent from self->net,
the lookup returns NULL, t becomes self, and vti6_update()
inserts the device into the creation netns hash. The new check
requires CAP_NET_ADMIN in the creation netns user_ns too.
SIOCADDTUNNEL and SIOCCHGTUNNEL on the fallback device keep
dev_net(dev), which equals init_net there. |
| In the Linux kernel, the following vulnerability has been resolved:
ipv6: validate extension header length before copying to cmsg
ip6_datagram_recv_specific_ctl() builds IPV6_{HOPOPTS,DSTOPTS,RTHDR}
cmsgs (and their IPV6_2292* legacy counterparts) by trusting the
on-wire hdrlen byte (ptr[1]) when computing the put_cmsg() length.
The length was validated only at parse time (ipv6_parse_hopopts(),
etc.). An nftables payload-write expression can rewrite hdrlen after
parsing and before the skb reaches recvmsg; the write itself is
in-bounds but put_cmsg() then reads up to ((hdrlen+1) << 3) = 2040
bytes from an 8-byte header. nftables is reachable from an
unprivileged user namespace, so this is an unprivileged
slab-out-of-bounds read:
BUG: KASAN: slab-out-of-bounds in put_cmsg+0x3ac/0x540
put_cmsg+0x3ac/0x540
udpv6_recvmsg+0xca0/0x1250
sock_recvmsg+0xdf/0x190
____sys_recvmsg+0x1b1/0x620
Add ipv6_get_exthdr_len() which validates that at least two bytes
are accessible before reading the hdrlen field, then checks the
computed length against skb_tail_pointer(skb), returning 0 on
failure. Extension headers are kept in the linear skb area by
pskb_may_pull() during input, so skb_tail_pointer() is the correct
bound.
Use ipv6_get_exthdr_len() at all non-AH call sites: the five
standalone cmsg blocks (HbH, 2292HbH, 2292DSTOPTS x2, 2292RTHDR)
and the three standard cases in the extension-header walk loop
(DSTOPTS, ROUTING, default). AH retains an inline bounds check
because its length formula differs ((ptr[1]+2)<<2).
The walk loop also gets a pre-read bounds check at the top to
validate ptr before any case accesses ptr[0] or ptr[1].
When the walk loop detects a corrupted header, return from the
function instead of continuing to process later socket options. |
| In the Linux kernel, the following vulnerability has been resolved:
xfrm: input: hold netns during deferred transport reinjection
Transport-mode reinjection stores a struct net pointer in skb->cb and
uses it later from xfrm_trans_reinject(). That pointer must stay valid
until the deferred callback runs.
Take a netns reference when queueing deferred reinjection work and drop
it after the callback completes. Use maybe_get_net() so the queueing
path does not revive a namespace that is already being torn down.
This keeps the existing workqueue design and fixes the netns lifetime
handling in one place for all users of xfrm_trans_queue_net(). |
| In the Linux kernel, the following vulnerability has been resolved:
l2tp: use refcount_inc_not_zero in l2tp_session_get_by_ifname
A reader in l2tp_session_get_by_ifname() can return a pointer to a
session whose refcount has reached zero. The getter takes its
reference with plain refcount_inc(), but every other session getter
in the same file (l2tp_v2_session_get, l2tp_v3_session_get, and the
corresponding _get_next variants) uses refcount_inc_not_zero()
because the IDR/RCU lookup can race with refcount_dec_and_test() ->
l2tp_session_free() -> kfree_rcu(). The ifname getter is the only
outlier; the inconsistency was raised on-list after 979c017803c4
("l2tp: use list_del_rcu in l2tp_session_unhash").
A reader inside rcu_read_lock_bh() that matches session->ifname can
be preempted between the strcmp() and the refcount_inc(). If the
last reference drops on another CPU in that window, the reader's
refcount_inc() runs on a counter that has reached zero. refcount_t
catches the addition-on-zero, prints "refcount_t: addition on 0;
use-after-free", saturates the counter, and returns the saturated
pointer to the caller. Session memory is held live by the in-flight
RCU read section, but the kfree_rcu() callback queued from
l2tp_session_free() will free it once the grace period closes; a
caller that dereferences the returned session past that point hits
a slab-use-after-free. On PREEMPT_RT local_bh_disable() is a per-CPU
sleeping lock and the preemption window is real; on stock PREEMPT
kernels local_bh_disable() is a preempt_count increment that closes
the cross-CPU race in practice (see below).
Use refcount_inc_not_zero() and continue the list walk on failure,
matching the other session getters in the file. The ifname getter
is the only session getter in net/l2tp/ that still uses the bare
refcount_inc() pattern; this change restores file-internal
consistency. The success path is unchanged. |
| In the Linux kernel, the following vulnerability has been resolved:
ip6: vti: Use ip6_tnl.net in vti6_changelink().
ip netns add ns1
ip netns add ns2
ip -n ns1 link add vti6_test type vti6 remote ::1 local ::2 key 7
ip -n ns1 link set vti6_test netns ns2
ip -n ns2 link set vti6_test type vti6 remote ::3 local ::4 key 9
ip netns del ns2
ip netns del ns1
[ 132.495484] ------------[ cut here ]------------
[ 132.497609] kernel BUG at net/core/dev.c:12376!
Commit 61220ab34948 ("vti6: Enable namespace changing") dropped
NETIF_F_NETNS_LOCAL from vti6 devices. A vti6 tunnel can then
move through IFLA_NET_NS_FD. After the move dev_net(dev) points
at the new netns while t->net stays at the creation netns.
vti6_changelink() and vti6_update() still use dev_net(dev) and
dev_net(t->dev). They unlink from one per netns hash and relink
into another. The creation netns is left with a stale entry.
cleanup_net() of that netns later walks freed memory.
Reachable from an unprivileged user namespace (unshare --user
--map-root-user --net). Cross tenant scope on container hosts. |
| In the Linux kernel, the following vulnerability has been resolved:
HID: wacom: Fix OOB write in wacom_hid_set_device_mode()
wacom_hid_set_device_mode() currently assumes that the HID_DG_INPUTMODE
usage is always located in the first field (field[0]) of the feature report.
However, a device can specify HID_DG_INPUTMODE in a different field.
If HID_DG_INPUTMODE is in a field other than the first one and the first
field has a report_count smaller than the usage_index of HID_DG_INPUTMODE,
this leads to an out-of-bounds write to r->field[0]->value.
Fix this by storing the field index of HID_DG_INPUTMODE in 'struct
hid_data' during feature mapping. In wacom_hid_set_device_mode(), use
this stored field index to access the correct field and add bounds
checks to ensure both the field index and the value index are within
valid ranges before writing. |
| In the Linux kernel, the following vulnerability has been resolved:
nfc: hci: fix out-of-bounds read in HCP header parsing
Both nfc_hci_recv_from_llc() and nci_hci_data_received_cb() read
packet->header from skb->data at function entry without first checking
that the buffer holds at least one byte. A malicious NFC peer can send
a 0-byte HCP frame that passes through the SHDLC layer and reaches
these functions, causing an out-of-bounds heap read of packet->header.
The same 0-byte frame, if queued as a non-final fragment, also causes
the reassembly loop to underflow msg_len to UINT_MAX, triggering
skb_over_panic() when the reassembled skb is written.
Fix this by adding a pskb_may_pull() check at the entry of each
function before packet->header is first accessed. The existing
pskb_may_pull() checks before the reassembled hcp_skb is cast to
struct hcp_packet remain in place to guard the 2-byte HCP message
header. |
| In the Linux kernel, the following vulnerability has been resolved:
xfrm: route MIGRATE notifications to caller's netns
xfrm_send_migrate() in net/xfrm/xfrm_user.c and pfkey_send_migrate()
in net/key/af_key.c both hardcode &init_net for the multicast that
announces a successful XFRM_MSG_MIGRATE / SADB_X_MIGRATE.
XFRM_MSG_MIGRATE arrives on a per-netns NETLINK_XFRM socket, and the
rest of the xfrm/af_key netlink path was made netns-aware in 2008.
The other 14 multicast paths in xfrm_user.c route their event using
xs_net(x), xp_net(xp) or sock_net(skb->sk); only the migrate path
was missed.
Two consequences of the init_net hardcoding:
1. The notification (selector, old/new endpoint addresses, and the
km_address) is delivered to listeners on init_net's
XFRMNLGRP_MIGRATE / pfkey BROADCAST_ALL groups rather than on
the issuing netns. An IKE daemon running in init_net therefore
receives migration notifications originating from any other
netns on the host.
2. An IKE daemon running inside a non-init netns and subscribed
to its own XFRMNLGRP_MIGRATE / pfkey groups never receives the
notification of its own migration. IKEv2 MOBIKE / address-update
handling inside a netns is silently broken.
Thread struct net through km_migrate() and the xfrm_mgr.migrate
function pointer, drop the &init_net override in xfrm_send_migrate()
and pfkey_send_migrate(), and pass the caller's net (already in
scope in xfrm_migrate() via sock_net(skb->sk)) all the way down.
struct xfrm_mgr is in-tree only and not exported as a stable API,
so the function-pointer signature change is internal.
pfkey_broadcast() is already netns-aware via net_generic(net,
pfkey_net_id) since the pernet conversion. The five other
pfkey_broadcast() callers in af_key.c already pass xs_net(x),
sock_net(sk) or a per-netns net, so this only removes the
&init_net outlier. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: conntrack: tcp: do not force CLOSE on invalid-seq RST without direction check
An unintended behavior in the TCP conntrack state machine allows a
connection to be forced into the CLOSE state using an RST packet with an
invalid sequence number.
Specifically, after a SYN packet is observed, an RST with an invalid SEQ
can transition the conntrack entry to TCP_CONNTRACK_CLOSE, regardless of
whether the RST corresponds to the expected reply direction. The relevant
code path assumes the RST is a response to an outgoing SYN, but does not
validate packet direction or ensure that a matching SYN was actually sent
in the opposite direction.
As a result, a crafted packet sequence consisting of a SYN followed by an
invalid-sequence RST can prematurely terminate an active NAT entry. This
makes connection teardown easier than intended.
So, tighten the state transition logic to ensure that RST-triggered
CLOSE transitions only occur when the RST is a valid response to a
previously observed SYN in the correct direction. |
| In the Linux kernel, the following vulnerability has been resolved:
xfrm: esp: restore combined single-frag length gate
The ESP out-of-place fast path appends the trailer in esp_output_head()
before esp_output_tail() allocates the destination page frag. The
head-side gate currently checks skb->data_len and tailen separately, but
the tail code allocates a single destination frag from the combined
post-trailer skb->data_len.
Reject the page-frag fast path when the combined aligned length exceeds a
page. Otherwise skb_page_frag_refill() may fall back to a single page while
the destination sg still spans the combined skb->data_len.
Restore this combined-length page gate for both IPv4 and IPv6. |
| In the Linux kernel, the following vulnerability has been resolved:
xfrm: iptfs: reset runtime state when cloning SAs
iptfs_clone_state() clones the IPTFS mode data with kmemdup(). This
copies runtime objects which must not be shared with the original SA,
including the embedded sk_buff_head, hrtimers, spinlock, and in-flight
reassembly/reorder state.
If xfrm_state_migrate() fails after clone_state() but before the later
init_state() call has reinitialized those fields, the cloned state can be
destroyed by xfrm_state_gc_task() with list and timer state copied from the
original SA. With queued packets this lets the clone splice and free skbs
owned by the original IPTFS queue, leading to use-after-free and
double-free reports in iptfs_destroy_state() and skb release paths.
Reinitialize the clone's runtime state before publishing it through
x->mode_data. Because clone_state() now publishes a destroyable mode_data
object before init_state(), take the mode callback module reference there.
Avoid taking it again from __iptfs_init_state() for the same object. |
| In the Linux kernel, the following vulnerability has been resolved:
dma-buf: fix UAF in dma_buf_fd() tracepoint
Once FD_ADD() returns, the fd is live in the file descriptor table
and a thread sharing that table can close() it before DMA_BUF_TRACE()
runs. The close drops the last reference, __fput() frees the dma_buf,
and the tracepoint then dereferences dmabuf to take dmabuf->name_lock
-- slab-use-after-free.
Split FD_ADD() back into get_unused_fd_flags() + fd_install() and
emit the tracepoint between them. While the fdtable slot is reserved
with a NULL file pointer, a racing close() returns -EBADF without
entering __fput(), so the dma_buf stays alive across the trace. Same
approach as commit 2d76319c4cbb ("dma-buf: fix UAF in dma_buf_put()
tracepoint").
This undoes the FD_ADD() conversion done in commit 34dfce523c90
("dma: convert dma_buf_fd() to FD_ADD()"); FD_ADD() has no place to
hook the tracepoint safely. |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: OOB read regression in smb_check_perm_dacl() ACE-walk loops
Commit d07b26f39246 ("ksmbd: require minimum ACE size in
smb_check_perm_dacl()") introduced a transposed bounds check:
if (offsetof(struct smb_ace, sid) + aces_size < CIFS_SID_BASE_SIZE)
Since offsetof(..sid) is 8 and CIFS_SID_BASE_SIZE is 8, this evaluates
to `aces_size < 0`. Because `aces_size` is always non-negative, this
check becomes dead code and never breaks the loop.
Worse, that commit removed the old 4-byte guard, meaning the loop now
reads `ace->size` (offset 2) even when `aces_size` is 0-3 bytes. This
re-opens a 2-byte heap out-of-bounds (OOB) read past the pntsd allocation
during subsequent SMB2_CREATE operations.
Fix this by properly transposing the comparison to require at least
16 bytes (8-byte offset + 8-byte SID base), matching the correct form
used in smb_inherit_dacl(). |
| In the Linux kernel, the following vulnerability has been resolved:
usb: musb: omap2430: Fix use-after-free in omap2430_probe()
In omap2430_probe(), of_node_put(np) is called prematurely before the
last access to np, leading to a use-after-free if the node's reference
count drops to zero. Move the of_node_put() calls after the last use of
np in both the success and error paths. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_fs: serialize DMABUF cancel against request completion
ffs_epfile_dmabuf_io_complete() calls usb_ep_free_request() on the
completed request but leaves priv->req, the back-pointer that
ffs_dmabuf_transfer() set on submission, pointing at the freed
memory. A later FUNCTIONFS_DMABUF_DETACH ioctl or
ffs_epfile_release() on the close path still sees priv->req
non-NULL under ffs->eps_lock:
if (priv->ep && priv->req)
usb_ep_dequeue(priv->ep, priv->req);
so usb_ep_dequeue() is called on a freed usb_request.
On dummy_hcd the dequeue path only walks a live queue and
pointer-compares, so the freed pointer reads without faulting and
KASAN requires an explicit check at the FunctionFS call site to
surface the use-after-free. On SG-capable in-tree UDCs the
dequeue path dereferences the supplied request immediately:
* chipidea's ep_dequeue() does
container_of(req, struct ci_hw_req, req) and reads
hwreq->req.status before acquiring its own lock.
* cdnsp's cdnsp_gadget_ep_dequeue() reads request->status first.
The narrower option of clearing priv->req via cmpxchg() in the
completion does not close the race: the completion runs without
eps_lock, so a cancel path holding eps_lock can still observe
priv->req non-NULL, race a concurrent completion that clears and
frees, and pass the freed pointer to usb_ep_dequeue(). A slightly
longer fix that moves the free into the cleanup work is needed.
Same class of lifetime race as the recent usbip-vudc timer fix [1].
Take eps_lock in the sole place that mutates priv->req from the
callback direction by moving usb_ep_free_request() out of the
completion into ffs_dmabuf_cleanup(), the existing work handler
scheduled by ffs_dmabuf_signal_done() on
ffs->io_completion_wq. Clear priv->req there under eps_lock
before freeing, and only clear if priv->req still names our
request (a subsequent ffs_dmabuf_transfer() on the same
attachment may have queued a new one).
This keeps the existing dummy_hcd sync-dequeue invariant: the
completion callback is still invoked by the UDC without
eps_lock held (dummy_hcd drops its own lock before calling the
callback), and the callback now takes no f_fs lock at all.
Serialization against the cancel path happens in cleanup, which
runs from the workqueue with no f_fs lock held on entry.
The priv ref count protects the containing ffs_dmabuf_priv:
ffs_dmabuf_transfer() takes a ref via ffs_dmabuf_get(), cleanup
drops it via ffs_dmabuf_put(), so priv stays live for the
cleanup even after the cancel path's list_del + ffs_dmabuf_put.
The ffs_dmabuf_transfer() error path no longer frees usb_req
inline: fence->req and fence->ep are set before usb_ep_queue(),
so ffs_dmabuf_cleanup() (scheduled by the error-path
ffs_dmabuf_signal_done()) owns the free regardless of whether
the queue succeeded.
Reproduced under KASAN on both detach and close paths against
dummy_hcd with an observability hook
(kasan_check_byte(priv->req) immediately before usb_ep_dequeue)
at the two FunctionFS cancel sites to surface the stale-pointer
access; the hook is not part of this patch. The KASAN
allocator / free stacks in the captured splats identify the
same request: alloc in dummy_alloc_request, free in
dummy_timer, fault reached from ffs_epfile_release (close) and
from the FUNCTIONFS_DMABUF_DETACH ioctl (detach). With the
patch applied, both paths are silent under the same hook.
The bug is reached from the FunctionFS device node, which in
real deployments is owned by the privileged gadget daemon
(adbd, UMS, composite gadget services, etc.); it is not
reachable from unprivileged userspace or from a USB host on the
cable. FunctionFS mounts default to GLOBAL_ROOT_UID, but the
filesystem supports uid=, gid=, and fmode= delegation to a
non-root gadget daemon, so on real deployments the attacker may
be a less-privileged service rather than root. |
| In the Linux kernel, the following vulnerability has been resolved:
thunderbolt: property: Reject u32 wrap in tb_property_entry_valid()
entry->value is u32 and entry->length is u16; the sum is performed in
u32 and wraps. A malicious XDomain peer can pick
value = 0xffffff00, length = 0x100 so the sum 0x100000000 wraps to 0
and passes the > block_len check. tb_property_parse() then passes
entry->value to parse_dwdata() as a dword offset into the property
block, reading attacker-directed memory far past the allocation.
For TEXT-typed entries with the "deviceid" or "vendorid" keys this
lands in xd->device_name / xd->vendor_name and is readable back via
the per-XDomain device_name / vendor_name sysfs attributes; the leak
is NUL-bounded (kstrdup() stops at the first zero byte) and
untargeted (the attacker picks a delta, not an absolute address).
DATA-typed entries are parsed into property->value.data but not
generically surfaced to userspace.
Use check_add_overflow() so a wrapped sum is rejected. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: scsi_transport_fc: Widen FPIN pname walker counter to u32
An adjacent Fibre Channel fabric actor that can deliver an FPIN ELS
frame to an lpfc or qla2xxx Linux initiator can trigger a non-return in
the generic FC transport. This is not a local userspace or IP network
path; the attacker must be able to inject fabric traffic, for example as
a compromised switch or fabric controller, or as a same-zone N_Port on a
fabric that permits source spoofing.
The Link-Integrity and Peer-Congestion FPIN walkers used a u8 loop
counter against the 32-bit on-wire pname_count field, and did not bound
pname_count by the descriptor body already validated by the TLV walker.
A pname_count of 256 therefore wraps the counter and keeps the loop
condition true indefinitely.
Factor the shared pname_list[] walk into one helper, widen the counter
to u32, and clamp pname_count against the entries that fit in the
descriptor body before iterating. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: target: iscsi: Fix CRC overread and double-free in iscsit_handle_text_cmd()
Two latent bugs in the Text-phase handler, both present since the
original LIO integration in commit e48354ce078c ("iscsi-target: Add
iSCSI fabric support for target v4.1"):
1) DataDigest CRC buffer overread (4 bytes past text_in).
text_in is kzalloc()'d at ALIGN(payload_length, 4). rx_size is then
incremented by ISCSI_CRC_LEN to make room for the received DataDigest
in the iovec, but the same (now-bumped) rx_size is passed as the
buffer length to iscsit_crc_buf():
if (conn->conn_ops->DataDigest) {
...
rx_size += ISCSI_CRC_LEN;
}
...
if (conn->conn_ops->DataDigest) {
data_crc = iscsit_crc_buf(text_in, rx_size, 0, NULL);
iscsit_crc_buf() walks rx_size bytes of text_in with crc32c(), so
when DataDigest is negotiated it reads 4 bytes past the end of the
text_in allocation. KASAN reproduces this directly on the unpatched
mainline tree as slab-out-of-bounds in crc32c() called from the Text
PDU path. The OOB bytes feed crc32c() and are then compared against
the initiator-supplied checksum, so the value does not flow back to
the attacker, but the kernel does read past the buffer on every Text
PDU with DataDigest=CRC32C.
Fix by passing the actual padded payload length
(ALIGN(payload_length, 4)) that was used for the kzalloc().
2) Stale cmd->text_in_ptr re-free (double-free) on ERL>0 bad DataDigest
drop.
On DataDigest mismatch with ErrorRecoveryLevel > 0 the handler
silently drops the PDU and lets the initiator plug the CmdSN gap:
kfree(text_in);
return 0;
cmd->text_in_ptr still points at the freed buffer. The next Text
Request on the same ITT re-enters iscsit_setup_text_cmd(), which
unconditionally does
kfree(cmd->text_in_ptr);
cmd->text_in_ptr = NULL;
freeing the same pointer a second time. Session teardown via
iscsit_release_cmd() has the same shape and hits the same double-free
if the connection is dropped before a second Text Request arrives.
On an unmodified mainline tree the bug-1 CRC overread fires first on
the initial valid Text Request and perturbs the subsequent state, so
#4 was isolated by building a kernel with only the bug-1 hunk of this
patch applied plus temporary printk() observability around the three
relevant kfree() sites. The observability prints are not part of
this patch. On that build, a three-PDU Text Request sequence after
login produces two back-to-back splats:
BUG: KASAN: double-free in iscsit_setup_text_cmd+0x??
BUG: KASAN: double-free in iscsit_release_cmd+0x??
showing the same pointer freed in the ERL>0 drop path and again in
iscsit_setup_text_cmd() (next Text Request on the same ITT) and once
more in iscsit_release_cmd() (session teardown). On distro kernels
with CONFIG_SLAB_FREELIST_HARDENED=y (default) the double-free
becomes a remote kernel BUG(); on non-hardened kernels it corrupts
the slab freelist.
Fix by clearing cmd->text_in_ptr after the kfree() in the ERL>0 drop
path. With both hunks applied #4 is directly observable on the stock
tree without observability printks; fixing bug-1 alone would mask #4
less, not more, so the hunks are submitted together.
Both fixes are one-liners. The Text PDU state machine is unchanged and
the wire protocol is unaffected. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: target: iscsi: Bound iscsi_encode_text_output() appends to rsp_buf
iscsi_encode_text_output() concatenates "key=value\0" records into
login->rsp_buf, an 8192-byte kzalloc(MAX_KEY_VALUE_PAIRS) buffer
allocated in iscsit_alloc_login_setup_buffer(). The three sprintf() call
sites in this function (lines 1398, 1411, 1424 in v7.1-rc2) never check
the remaining buffer capacity:
*length += sprintf(output_buf, "%s=%s", er->key, er->value);
*length += 1;
output_buf = textbuf + *length;
The 8192-byte ceiling at iscsi_target_check_login_request() bounds the
*input* Login PDU payload, but a single PDU can carry up to 2048 minimal
four-byte "a=b\0" pairs, each unknown key expanding to a 16-byte
"a=NotUnderstood\0" output record via iscsi_add_notunderstood_response().
2048 * 16 = 32 KiB of output into an 8 KiB buffer, producing a ~24 KiB
heap overrun in the kmalloc-8k slab.
The fix introduces a static iscsi_encode_text_record() helper that uses
snprintf() with a per-call bounds check against the remaining buffer,
and threads a u32 textbuf_size parameter through
iscsi_encode_text_output(). Both call sites in
iscsi_target_handle_csg_zero() (PHASE_SECURITY) and
iscsi_target_handle_csg_one() (PHASE_OPERATIONAL) pass
MAX_KEY_VALUE_PAIRS. On overflow the encoder logs the condition, calls
iscsi_release_extra_responses() to drop queued records, and returns -1;
both caller sites now emit ISCSI_STATUS_CLS_INITIATOR_ERR /
ISCSI_LOGIN_STATUS_INIT_ERR via iscsit_tx_login_rsp() before returning,
so the initiator sees an explicit failed-login response rather than a
silent connection drop. (Prior to this patch only the PHASE_OPERATIONAL
caller did that; the PHASE_SECURITY caller is converted to the same
shape.) |
