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CVE-2026-89611
Crítica · 9.8
11/09/2026
ntfs: validate non-resident attribute offsets
In the Linux kernel, the following vulnerability has been resolved:
ntfs: validate non-resident attribute offsets
ntfs_attr_update_meta() shifts the attribute name when converting between
non-sparse and sparse attributes. Converting to sparse also adds the
compressed_size field before the name and mapping pairs, requiring eight
additional bytes in the attribute record.
However, the validator does not check that name_offset is within safe
boundaries for these operations or that the additional space is available.
A malicious MFT record could set name_offset such that:
1. The name is positioned at the very end of a non-sparse attribute.
Converting to sparse would shift the name forward by 8 bytes,
writing beyond the attribute boundary.
2. The name overlaps with the mapping pairs, causing corruption during
conversion.
Add validation to ensure:
- For named attributes, name_offset is within valid bounds
- Name does not extend beyond the attribute or overlap with mapping pairs
- For non-sparse, non-compressed attributes, eight bytes are available
after mapping_pairs_offset for the compressed_size field
The space check also covers unnamed attributes, for which name_offset = 0
is valid and no name range needs to be checked.
CVE-2026-89610
Crítica · 9.8
11/09/2026
ntfs: verify run length exceeding volume boundary
In the Linux kernel, the following vulnerability has been resolved:
ntfs: verify run length exceeding volume boundary
The mapping pairs decoder validates that the starting LCN is within the
volume but does not check if the run extends beyond the volume boundary.
A malformed NTFS image with a crafted mapping pairs array could cause
the kernel to access memory beyond the volume boundary, potentially leading
to memory corruption and privilege escalation.
Add validation to ensure lcn + length stays within nr_clusters.
CVE-2026-89558
Crítica · 9.8
11/09/2026
md/raid10: fix still_degraded being inverted in raid10_sync_request()
In the Linux kernel, the following vulnerability has been resolved:
md/raid10: fix still_degraded being inverted in raid10_sync_request()
Commit fe6a19d40ceb ("md/md-bitmap: merge md_bitmap_start_sync() into
bitmap_operations") converted still_degraded from int to bool, but
inverted the assignment in the loop that checks whether the array will
still be degraded after the current device is recovered:
"still_degraded = 1" became "still_degraded = false".
As a result, recovering a device while another mirror is still missing
calls md_bitmap_start_sync() with degraded == false, which clears bitmap
bits that the still-missing device needs. When that device is re-added,
its bitmap-based recovery finds the bits already cleared and skips every
region written while the array was degraded, so it is marked In_sync
while holding stale data: silent corruption.
Reproducer (raid10 near=2, 4 disks, internal bitmap):
- fail and remove one disk of each mirror pair
- write to the degraded array
- re-add both disks and let recovery finish
- "check" reports mismatch_cnt=262272 after 256 MiB of degraded
writes and file contents differ; the second disk's "recovery"
completes in milliseconds because everything is skipped
The same conversion in raid1 got it right (still_degraded = true).
Restore the correct value.
CVE-2026-89555
Crítica · 9.8
11/09/2026
mpls: reload header after pskb_may_pull()
In the Linux kernel, the following vulnerability has been resolved:
mpls: reload header after pskb_may_pull()
mpls_select_multipath() calls mpls_multipath_hash() to choose a nexthop
when an MPLS route has multiple nexthops. While walking the MPLS label
stack, the hash routine caches hdr for the current label. After finding
the bottom-of-stack label, it calls pskb_may_pull() before reading the
inner IP header.
If an skb is constructed with the inner IP header in nonlinear data and
insufficient tailroom in the linear head, pskb_may_pull() calls
pskb_expand_head() to replace the skb head and free the old one. This
leaves hdr pointing to freed memory. The IPv6 path can invalidate hdr
again when it performs a second pull for the larger header.
The issue was found through static analysis. A reproducer sending a legal
Geneve packet through a bareudp/MPLS multipath setup triggered the same
KASAN report in 2 of 2 unpatched runs:
BUG: KASAN: slab-use-after-free in mpls_select_multipath
Read of size 1 at addr ffff88800ecc6e20 by task ksoftirqd/1/23
Call Trace:
mpls_select_multipath
mpls_forward
__netif_receive_skb_list_core
netif_receive_skb_list_internal
napi_complete_done
gro_cell_poll
__napi_poll
net_rx_action
Freed by task 23:
kfree
pskb_expand_head
__pskb_pull_tail
mpls_select_multipath
Reload hdr from the current skb head after each successful pull before
deriving the inner IPv4 or IPv6 header pointer.
CVE-2026-89551
Crítica · 9.8
11/09/2026
SUNRPC: xdr_buf_trim: clamp buf->len to avoid underflow
In the Linux kernel, the following vulnerability has been resolved:
SUNRPC: xdr_buf_trim: clamp buf->len to avoid underflow
xdr_buf_trim() trims `len` bytes from the tail of an xdr_buf by
walking the tail, pages, and head iovecs. Each per-section step
uses min_t() so it never removes more bytes than that section
holds, but the final accounting at the fix_len label subtracts the
total bytes actually consumed from buf->len without any clamp:
fix_len:
buf->len -= (len - trim);
When the caller has set buf->len to a value smaller than the sum
of the iov_lens, (len - trim) can exceed buf->len and the unsigned
subtraction wraps to near UINT_MAX. gss_krb5_unwrap_v2() reaches
xdr_buf_trim() in exactly that state:
buf->head[0].iov_len -= GSS_KRB5_TOK_HDR_LEN + headskip;
buf->len = len - (GSS_KRB5_TOK_HDR_LEN + headskip);
xdr_buf_trim(buf, ec + GSS_KRB5_TOK_HDR_LEN + tailskip);
buf->len is a small wire-derived value while the iov_lens are at
page scale, so the per-section loops legitimately consume far more
bytes than buf->len records. The wrapped buf->len then propagates
as the authoritative stream bound into every downstream XDR
decoder.
Fix by clamping the decrement so buf->len bottoms out at zero:
buf->len -= min_t(unsigned int, buf->len, len - trim);
On the normal path where the iov_lens sum to buf->len, (len - trim)
is always <= buf->len and the result is identical to before. No
callers change behavior outside the underflow case.
CVE-2026-89550
Crítica · 9.8
11/09/2026
SUNRPC: svcauth_gss: enforce krb5 token minimum length
In the Linux kernel, the following vulnerability has been resolved:
SUNRPC: svcauth_gss: enforce krb5 token minimum length
svcauth_gss_unwrap_priv() validates only an upper bound on the
wire-supplied opaque length before handing the buffer to
gss_unwrap():
if (len > xdr_stream_remaining(xdr))
goto unwrap_failed;
offset = xdr_stream_pos(xdr);
...
maj_stat = gss_unwrap(ctx, offset, offset + len, buf);
The wire value `len` flows unchanged as the upper bound into the
krb5 unwrap path, so a len in [0, 16] passes this check and is
handed to gss_unwrap(). For a krb5 v2 context that lands in
gss_krb5_unwrap_v2(), which reads the 16-byte RFC 4121 token
header fields at ptr+4 and ptr+6 and then calls rotate_left()
before any integrity check. With a sub-header length the header
reads run past the token, and _rotate_left()'s `shift %= buf->len`
path can divide by zero when buf->len has been driven to zero by
the truncated token. A header-only token (len == 16) is equally
invalid: with a non-zero RRC field and the opaque blob ending at
the XDR buffer boundary, rotate_left() builds a zero-length
subbuffer, reaching the same division.
Reject the token at the server entry point before it reaches the
krb5 unwrap core. A valid sealed RFC 4121 token must contain
the 16-byte header plus at least some encrypted payload.
Fix by adding a minimum-length check immediately after the
existing upper-bound check:
if (len <= GSS_KRB5_TOK_HDR_LEN)
goto unwrap_failed;
CVE-2026-89546
Crítica · 9.8
11/09/2026
SUNRPC: close backchannel before destroying callback service
In the Linux kernel, the following vulnerability has been resolved:
SUNRPC: close backchannel before destroying callback service
A backchannel receive can complete a request while the NFS callback
service is being torn down. xprt_complete_bc_request() removes the
request from bc_pa_list, drops bc_alloc_count, marks the request in use,
and then asks xprt_enqueue_bc_request() to hand it to the callback
service.
If teardown has already cleared xprt->bc_serv, xprt_enqueue_bc_request()
currently returns without enqueueing or freeing the committed request.
The xprt_get() taken on entry is leaked as well. If the producer wins
the race before bc_serv is cleared, it can also enqueue onto sv_cb_list
after nfs_callback_down() has stopped the callback threads, leaving the
request linked to a svc_serv that is about to be freed.
Close the producer side before callback threads are stopped. Add
xprt_svc_shutdown_bc() to clear xprt->bc_serv under bc_pa_lock, and call
it on callback shutdown and callback-start failure before stopping the
service threads. Requests that lose the NULL transition in
xprt_enqueue_bc_request() are released through the normal backchannel
free path after balancing bc_slot_count. Finally, drain any remaining
sv_cb_list requests after the callback threads have stopped and before
svc_destroy() frees the service.
CVE-2026-89542
Crítica · 9.8
11/09/2026
SUNRPC: harden gss_krb5_unwrap_v2 against short tokens
In the Linux kernel, the following vulnerability has been resolved:
SUNRPC: harden gss_krb5_unwrap_v2 against short tokens
gss_krb5_unwrap_v2() reads the EC and RRC header fields at ptr+4 and
ptr+6 before validating that the token is at least GSS_KRB5_TOK_HDR_LEN
(16) bytes long, and its rotate_left() helper passes buf->len - base
to xdr_buf_subsegment() without verifying that base <= buf->len. When
a caller hands in a sub-16-byte token, or a token whose declared len
leaves base past the end of the buffer, three distinct failures follow:
gss_krb5_unwrap_v2(offset, len, buf)
ptr = buf->head[0].iov_base + offset
ec = *(ptr + 4) /* OOB read on short head */
rrc = *(ptr + 6) /* OOB read on short head */
rotate_left(offset + 16, buf, rrc)
xdr_buf_subsegment(buf, &subbuf,
base, buf->len - base) /* u32 wrap when base > len */
_rotate_left(&subbuf, shift)
shift %= buf->len /* divide-by-zero when base == len */
After decryption, the cleanup arithmetic has the same shape:
movelen = min_t(unsigned int, buf->head[0].iov_len, len);
movelen -= offset + GSS_KRB5_TOK_HDR_LEN + headskip;
BUG_ON(offset + GSS_KRB5_TOK_HDR_LEN + headskip + movelen >
buf->head[0].iov_len);
The BUG_ON re-adds the value just subtracted, so it reduces to
min(A, B) > A and is permanently false; it cannot catch the unsigned
underflow of movelen, which then drives a ~UINT_MAX-byte memmove().
Add four defense-in-depth guards inside the unwrap core so it is safe
regardless of what its callers validate:
- reject tokens with len - offset < GSS_KRB5_TOK_HDR_LEN before
touching ptr+4/ptr+6;
- bail from rotate_left() when buf->len <= base, covering both the
underflow and zero-length cases;
- return early from _rotate_left() when buf->len is zero, so the
shift %= buf->len modulo cannot fault;
- replace the dead BUG_ON with a live check that returns
GSS_S_DEFECTIVE_TOKEN before the movelen subtraction.
CVE-2026-89541
Crítica · 9.8
11/09/2026
SUNRPC: harden gss_unwrap_resp_priv length checks
In the Linux kernel, the following vulnerability has been resolved:
SUNRPC: harden gss_unwrap_resp_priv length checks
gss_unwrap_resp_priv() validates the RPCSEC_GSS opaque length with
offset = (u8 *)(p) - (u8 *)head->iov_base;
if (offset + opaque_len > rcv_buf->len)
goto unwrap_failed;
maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset,
offset + opaque_len, rcv_buf);
Both operands are u32 and the sum is computed in u32. A reply with
opaque_len near 0xffffffff makes offset + opaque_len wrap to a small
value that is below rcv_buf->len, so the bound check passes and
gss_unwrap() is called with end < begin. The check also lacks a
lower bound, so any opaque_len in [0, GSS_KRB5_TOK_HDR_LEN) is
accepted and forwarded to gss_krb5_unwrap_v2(), whose pre-decrypt
header reads at ptr+4 and ptr+6 then run past the token.
A krb5p NFS server returning a crafted RPCSEC_GSS reply can drive
the client into out-of-bounds reads in gss_krb5_unwrap_v2() and the
rotate_left() loop that follows.
Fix by replacing the single combined check with three guards that
are safe in u32 arithmetic and that enforce the RFC 4121 minimum
outer token length:
if (offset > rcv_buf->len)
goto unwrap_failed;
if (opaque_len > rcv_buf->len - offset)
goto unwrap_failed;
if (opaque_len < GSS_KRB5_TOK_HDR_LEN)
goto unwrap_failed;
The first guard makes the subtraction in the second guard
unconditionally safe; offset is derived from a successful
xdr_inline_decode() in the head kvec, so in practice it already
satisfies the bound. The floor mirrors the server-side check added
in commit 5b757c2e57a5 ("SUNRPC: svcauth_gss: enforce krb5 token
minimum length").
CVE-2026-89538
Crítica · 9.8
11/09/2026
SUNRPC: Reject krb5 v2 wrap tokens with oversized ec field
In the Linux kernel, the following vulnerability has been resolved:
SUNRPC: Reject krb5 v2 wrap tokens with oversized ec field
gss_krb5_unwrap_v2() sets buf->len to a logical
length, which can be much smaller than head[0].iov_len
(the allocated receive-page capacity). It then calls
xdr_buf_trim() with a trim length derived from the 16-bit
"extra count" (ec) field in the Kerberos v2 token header.
The ec field is authenticated by the post-decrypt memcmp()
against the encrypted header copy, so a randomly-mutated
value is rejected. However, any peer holding a valid GSS
context can legitimately encrypt a token whose ec exceeds
the plaintext length. Per RFC 4121, such a token is
structurally malformed.
Although xdr_buf_trim() now clamps the buf->len subtraction
to avoid unsigned underflow, the buffer is still left in a
semantically invalid state (zero length, inconsistent iov
lengths) when ec is oversized.
Reject these tokens before calling xdr_buf_trim(), giving
callers a well-defined GSS_S_DEFECTIVE_TOKEN error and
keeping the xdr_buf internally consistent. The wrapped blob
begins at a nonzero offset -- both callers pass len as
offset + opaque_len -- so buf->len still counts the offset
bytes that precede the blob. Compare the trim length
against the remaining wrapped segment, buf->len - offset,
rather than the whole buffer; comparing against buf->len
alone leaves an offset-wide window in which an oversized ec
passes the test and xdr_buf_trim() cuts into the bytes ahead
of the blob.
CVE-2026-89536
Crítica · 9.8
11/09/2026
SUNRPC: wait for in-flight client TLS handshake callback
In the Linux kernel, the following vulnerability has been resolved:
SUNRPC: wait for in-flight client TLS handshake callback
xs_tls_handshake_sync() gives xs_tls_handshake_done() a reference to the
lower transport before submitting the handshake request. On timeout or
signal, the synchronous waiter drops that reference after calling
tls_handshake_cancel().
handshake_req_cancel() returns false when handshake_complete() has
already marked the request complete. In that case the completion callback
can still be running, so dropping the callback-owned reference in the
waiter can free the lower transport before xs_tls_handshake_done() stores
xprt_err or drops its own reference.
If cancellation loses to completion, wait until xs_tls_handshake_done()
signals handshake_done and let the callback release its reference. This
mirrors the server-side handshake lifetime handling and keeps the timeout
or signal return value unchanged.
CVE-2026-89533
Crítica · 9.8
11/09/2026
svcrdma: Fix offset arithmetic in read_chunk_range
In the Linux kernel, the following vulnerability has been resolved:
svcrdma: Fix offset arithmetic in read_chunk_range
svc_rdma_read_chunk_range() walks a Read chunk's segment list to
build a sub-range starting at byte offset and spanning length bytes
for a Position-Zero or Call chunk. Two arithmetic defects in the
per-segment loop produce wrong DMA lengths and a u32 underflow:
pcl_for_each_segment(segment, chunk) {
if (offset > segment->rs_length) {
offset -= segment->rs_length;
continue;
}
dummy.rs_handle = segment->rs_handle;
dummy.rs_length = min_t(u32, length,
segment->rs_length) - offset;
dummy.rs_offset = segment->rs_offset + offset;
First, the skip predicate uses '>' instead of '>='. When offset
equals the segment's full rs_length, the segment is fully consumed
and should be skipped, but the loop falls through into the body.
The resulting dummy.rs_length is min_t(u32, length, rs_length) -
rs_length, which underflows to a near-UINT_MAX u32 when length is
smaller than rs_length, or is zero otherwise.
Second, the length formula subtracts offset from the min_t() result
rather than from segment->rs_length before the cap. For offset > 0
the segment's residual is rs_length - offset, not rs_length, so the
cap must be applied to the residual. With the current bracketing,
whenever length is smaller than rs_length - offset the per-segment
length becomes length - offset instead of length, silently dropping
offset bytes from the rebuilt chunk. Combined with the boundary
case above it also enables the u32 underflow path, which propagates
a huge nr_bvec into svc_rdma_build_read_segment() and a multi-MiB
kmalloc_array_node() in svc_rdma_get_rw_ctxt().
Additionally, svc_rdma_read_call_chunk() can invoke this function
with length == 0 when the last Read chunk ends exactly at the end
of the Call chunk. With the corrected >= predicate, every segment
is skipped and the function returns the initial -EINVAL, rejecting
a valid request. Return success immediately when length is zero.
Also break out of the loop once length is fully consumed to avoid
passing zero-length segments to svc_rdma_build_read_segment().
Fix by using '>=' so a fully-consumed segment is skipped, by
moving '- offset' inside min_t() so the cap is applied to the
segment's residual length, by returning success for zero-length
requests, and by stopping iteration when the requested range has
been consumed.
CVE-2026-89532
Crítica · 9.1
11/09/2026
svcrdma: Fix pcl_for_each_segment for empty chunks
In the Linux kernel, the following vulnerability has been resolved:
svcrdma: Fix pcl_for_each_segment for empty chunks
When a parsed chunk list contains a chunk whose ch_segcount is zero,
pcl_for_each_segment computes its inclusive upper bound as
&chunk->ch_segments[ch_segcount - 1]. ch_segcount is u32, so the
subtraction wraps to 0xFFFFFFFF and the bound lands far past the
ch_segments flex array. The loop body then walks unrelated memory at
sizeof(struct svc_rdma_segment) stride until it faults.
A zero-segcount chunk is reachable from the wire:
xdr_check_write_chunk() only rejects segcount values greater than
rc_maxpages, and pcl_alloc_write() links a freshly allocated chunk
onto rc_write_pcl/rc_reply_pcl before its segment-fill loop runs,
so a Write or Reply chunk advertising zero segments leaves
ch_segcount == 0 on the list. When the transport has negotiated
Send-With-Invalidate, svc_rdma_get_inv_rkey() iterates all four
PCLs with pcl_for_each_segment and dereferences segment->rs_handle
on each iteration, turning the underflow into an out-of-bounds read
and a general protection fault.
xdr_check_write_list / xdr_check_reply_chunk
pcl_alloc_write()
chunk = pcl_alloc_chunk(...) /* ch_segcount = 0 */
list_add_tail(&chunk->ch_list, &pcl->cl_chunks)
/* fill loop iterates zero times for wire segcount 0 */
svc_rdma_get_inv_rkey()
pcl_for_each_chunk(rc_write_pcl)
pcl_for_each_segment(segment, chunk)
pos <= &ch_segments[0u - 1u] /* 0xFFFFFFFF */
segment->rs_handle /* OOB read -> GPF */
Fix by switching the macro to a half-open upper bound that uses
ch_segcount directly. For ch_segcount == 0 the loop start equals the
loop end and the body is skipped; for ch_segcount > 0 the iteration
range is unchanged. All six existing call sites in
net/sunrpc/xprtrdma/svc_rdma_recvfrom.c and
net/sunrpc/xprtrdma/svc_rdma_rw.c remain correct under the new bound,
so no caller changes are needed.
CVE-2026-89537
Crítica · 9.1
11/09/2026
SUNRPC: Reject short RFC 4121 MIC tokens in gss_krb5_verify_mic_v2
In the Linux kernel, the following vulnerability has been resolved:
SUNRPC: Reject short RFC 4121 MIC tokens in gss_krb5_verify_mic_v2
gss_krb5_verify_mic_v2() reads the token ID at ptr[0..1], the flags
byte at ptr[2], and padding at ptr[3..7], then passes
ptr + GSS_KRB5_TOK_HDR_LEN and cksum_len to gss_krb5_mic_build_sg().
None of these accesses check read_token->len first.
The minimum safe token size is GSS_KRB5_TOK_HDR_LEN (16) plus
ctx->krb5e->cksum_len (12-24, depending on the enctype). All callers
accept shorter tokens from the wire:
- gss_unwrap_resp_integ() enforces only an upper bound
(offset + len <= rcv_buf->len) before allocating
mic.data = kmalloc(len) and passing it to gss_verify_mic().
A malicious NFS server can therefore supply a short checksum
opaque, producing a small slab allocation that the Kerberos MIC
verifier reads past.
- gss_validate() enforces only len <= RPC_MAX_AUTH_SIZE (400)
before passing the wire-supplied length to
gss_validate_seqno_mic(), which constructs a mic xdr_netobj
and calls gss_verify_mic().
- svcauth_gss_verify_header() enforces only
checksum.len >= XDR_UNIT (4 bytes) before dispatching to
gss_verify_mic().
- svcauth_gss_unwrap_integ() checks only that the checksum fits
in gsd->gsd_scratch.
Add a length guard at the top of gss_krb5_verify_mic_v2(), before any
ptr[] access or scatterlist construction. Well-formed MIC tokens from
gss_krb5_get_mic_v2() already have exactly GSS_KRB5_TOK_HDR_LEN +
cksum_len bytes, so valid traffic is unaffected.
CVE-2026-89530
Crítica · 9.8
11/09/2026
svcrdma: Reject inline replies that overflow the pull-up buffer
In the Linux kernel, the following vulnerability has been resolved:
svcrdma: Reject inline replies that overflow the pull-up buffer
An RPC-over-RDMA client can request a reply, such as an NFS READ
payload, without providing a Write list or a Reply chunk to carry
it. When such a reply needs more scatter/gather entries than the
device's Send Queue supports, svc_rdma_pull_up_needed() selects
pull-up and svc_rdma_pull_up_reply_msg() linearizes the whole
reply into sctxt->sc_xprt_buf. That buffer is only sc_max_req_size
bytes, while the reply on this path is bounded only by the client's
request, so svc_rdma_xb_linearize() copies past the end of the
buffer and corrupts adjacent slab memory. The oversized length is
then stored in sc_sges[0].length and posted, so the device also
reads beyond the mapped region.
The SGE-exhaustion branch is the only pull-up path that can exceed
the buffer: the threshold branch pulls up only replies smaller
than RPCRDMA_PULLUP_THRESH, and replies that fit the device's SGE
budget are sent directly without linearization. Make
svc_rdma_pull_up_needed() report -E2BIG when the reply it would
pull up cannot fit sc_max_req_size, and fail the request with
ERR_CHUNK as RFC 8166 Section 4.5.3 directs rather than dropping
the connection.
The helper no longer answers a simple yes/no question: it now
reports pull-up, no pull-up, or -E2BIG for a reply too large to
linearize. Rename svc_rdma_pull_up_needed() to
svc_rdma_check_pull_up() so its name no longer implies a boolean
predicate.
CVE-2026-89526
Crítica · 9.8
11/09/2026
svcrdma: Validate Read chunk positions before reconstruction
In the Linux kernel, the following vulnerability has been resolved:
svcrdma: Validate Read chunk positions before reconstruction
The RPC/RDMA Read chunk position field is supplied by the remote
client and stored verbatim in the parsed chunk list.
xdr_count_read_segments() checks only 4-byte alignment; it never
compares the position against the received inline body length.
In the single-chunk path, svc_rdma_read_complete_one() splits the
head and tail kvecs at ch_position. A position past the inline
body underflows the tail length, exposing adjacent slab memory to
the upper XDR decoder.
In the multi-chunk path, svc_rdma_read_multiple_chunks() computes
gap lengths between chunks as unsigned subtractions from
ch_position. Overlapping Read chunks cause these subtractions to
underflow. A final position past the inline body likewise
underflows the trailing gap length. svc_rdma_copy_inline_range()
then copies past the receive buffer into request pages that are
returned to the client through the Reply channel.
Bound inline-range copies in svc_rdma_copy_inline_range() against
the decoded inline RPC body saved in rc_saved_arg. Reject a
single Read chunk positioned beyond that body, and reject
multi-chunk lists where accumulated read bytes exceed the next
chunk's position. Apply the same position and overlap checks in
the call-chunk interleaving path.
CVE-2026-89495
Crítica · 9.8
11/09/2026
ocfs2: bound namelen in dlm_migrate_request_handler
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: bound namelen in dlm_migrate_request_handler
Patch series "ocfs2/dlm: bound peer-controlled lengths in the o2dlm".
The o2dlm receive handlers trust u8 length and count fields from the wire
without bounding them, so a node in a DLM domain can corrupt or panic any
other node with a malformed message. Three defects:
- dlm_migrate_request_handler() passes migrate->namelen unchecked to
dlm_init_mle(), which memcpy()s it into the 32-byte mname[] of an
o2dlm_mle slab object: a heap out-of-bounds write of up to ~215
attacker-controlled bytes.
- dlm_mig_lockres_handler() passes mres->lockname_len unchecked to
dlm_init_lockres(), which memcpy()s it into the 32-byte o2dlm_lockname
slab object: a heap out-of-bounds write of up to ~223 bytes.
- the same handler trusts mres->num_locks without checking that the
message is large enough to hold that many entries, so
dlm_process_recovery_data() walks mres->ml[] past the kmalloc(data_len)
copy and trips a BUG_ON (an out-of-bounds read ending in a panic).
The other o2dlm receive handlers already reject an oversized name; the
migration and recovery handlers have omitted it since the DLM was added
(see the Fixes tags). Patch 1 bounds namelen; patch 2 validates
lockname_len, num_locks, and the payload size. Conforming recovery and
migration traffic is unaffected.
o2net authenticates peers only by the DLM domain key, so any node that has
joined the domain -- including a compromised or malicious member -- can
send these messages. There is no local trigger; the attacker must already
be a member of the cluster.
Each sink was confirmed under KASAN with an out-of-tree module mirroring
it exactly -- a kmem_cache/kmalloc of the real destination size, then the
same unclamped memcpy/loop: slab-out-of-bounds Write for the two writes,
Read for the recovery walk, and a panic. A userspace AddressSanitizer
build faults identically under -m32 and -m64. Scrubbed logs are available
on request.
I reported this privately to security@kernel.org and the ocfs2 maintainers
on 2026-06-20; with no response after the standard embargo period I am
posting the fix publicly. I have no embargo requirement.
This patch (of 2):
A node receiving a DLM_MIGRATE_REQUEST message trusts the peer-supplied
name length (migrate->namelen) without bounding it. dlm_init_mle() then
copies that many bytes into the fixed DLM_LOCKID_NAME_MAX-byte mname[]
array of an o2dlm_mle slab object, so a malformed message from a cluster
peer overflows the slab object by up to ~215 bytes: a heap out-of-bounds
write of attacker-controlled data, reachable by any node in the domain.
Reject an oversized name, the way dlm_master_request_handler() and the
other o2dlm receive handlers already do; the migration handler omits the
check entirely. Conforming messages are unaffected.
CVE-2026-89494
Crítica · 9.8
11/09/2026
ocfs2: validate lengths in dlm_mig_lockres_handler
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: validate lengths in dlm_mig_lockres_handler
A node receiving a DLM_MIG_LOCKRES message trusts several fields of the
peer-supplied dlm_migratable_lockres without validation. num_locks and
lockname_len are bounded only on the sending side, and the message is
never checked to actually carry num_locks migratable_lock entries. As a
result dlm_process_recovery_data() walks mres->ml[0..num_locks) past the
kmalloc(data_len) copy of the message (an out-of-bounds read that ends in
a BUG_ON panic), and dlm_init_lockres() copies lockname_len bytes into the
fixed 32-byte o2dlm_lockname slab object (a heap out-of-bounds write).
Both are reachable by any node in the domain.
Validate these fields right after dlm_grab(), before anything uses them --
including the not-joined error path, which already prints mres->lockname
with the unbounded lockname_len as a %.*s precision. Reject the message
unless lockname_len <= DLM_LOCKID_NAME_MAX, num_locks <=
DLM_MAX_MIGRATABLE_LOCKS (the bound the sender already asserts), and the
payload is large enough to hold the claimed locks. Conforming recovery
and migration messages are unaffected.
CVE-2026-89492
Crítica · 9.8
11/09/2026
ocfs2: validate directory-index entry counts when reading metadata
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: validate directory-index entry counts when reading metadata
ocfs2_validate_dx_leaf() and ocfs2_validate_dx_root() check the ECC and
signature of an indexed-directory block before it reaches higher-level
callers, but neither validator bounds the ocfs2_dx_entry_list counts
against the capacity of the block that holds them.
ocfs2_dx_dir_search() then walks
for (i = 0; i < le16_to_cpu(entry_list->de_num_used); i++)
dx_entry = &entry_list->de_entries[i];
over de_num_used entries with no bounds check. entry_list is either
dx_leaf->dl_list (from ocfs2_read_dx_leaf) or, for an inline root,
dx_root->dr_entries. A crafted on-disk image can set de_num_used (and
de_count, which is the __counted_by_le() bound of de_entries) to 0xffff
and make the walk read far past the end of the 4KB metadata block, giving
a slab out-of-bounds read reachable from any path lookup, stat() or open()
on an indexed directory once the image is mounted.
Commit 775c17386a6f ("ocfs2: validate dx_root extent list fields during
block read") already bounds dr_list for the non-inline dx_root, but left
the inline dr_entries path and the dx_leaf dl_list unchecked. Add the
same read-time validation for both entry lists: de_count must equal the
capacity of the block (ocfs2_dx_entries_per_leaf()/per_root()) and
de_num_used must not exceed de_count, rejecting corrupted metadata with
-EFSCORRUPTED before ocfs2_dx_dir_search() can walk an out-of-range entry
array.
de_count is always written as exactly the block capacity when a leaf or
inline root is formatted, so the equality check does not reject any valid
image.
Found by 0sec automated security-research tooling (https://0sec.ai).
CVE-2026-89485
Crítica · 9.8
11/09/2026
lockd: pin next file across nlm_inspect_file lock-drop
In the Linux kernel, the following vulnerability has been resolved:
lockd: pin next file across nlm_inspect_file lock-drop
nlm_traverse_files() pins the current file with f_count++ across
a mutex_unlock for nlm_inspect_file(), but nothing pins the saved
next pointer. A concurrent nlm_release_file() can kfree the next
file during the unlock window, and the iterator dereferences freed
memory on the next loop step.
Pin both current and next before the lock-drop. Advance by
swapping the pinned cursors at the end of each iteration so next
is always held alive across the unlock.
Always call nlm_file_release() after dropping the iteration pin,
regardless of whether the file matched the predicate. Use
nlm_file_inuse(), which does a live walk of the inode lock list,
rather than the cached f_locks field, so skipped files that never
ran nlm_inspect_file() are evaluated correctly.
Because every file in a hash bucket is now pinned and released,
files skipped by the is_failover_file predicate that have no
locks, blocks, shares, or external references are deleted during
traversal. The old code never evaluated skipped files for
cleanup. The new behavior is intentional: such files are stale
and should not persist in the table.
CVE-2026-89482
Crítica · 9.8
11/09/2026
nvme-tcp: do not accept C2HData based on blk_rq_payload_bytes() alone
In the Linux kernel, the following vulnerability has been resolved:
nvme-tcp: do not accept C2HData based on blk_rq_payload_bytes() alone
Commit 25e5cb780e62 ("nvme-tcp: fix possible crash in write_zeroes
processing") established that blk_rq_payload_bytes() must not be read
without first checking blk_rq_nr_phys_segments(), and recorded the
result in nvme_tcp_setup_cmd_pdu() as req->data_len. The receive side
was left as it was.
The two differ for REQ_OP_WRITE_ZEROES, which has no physical segments
but a non-zero blk_rq_bytes(), so setup leaves req->iter untouched
while the receive gate lets a C2HData through and nvme_tcp_recv_data()
copies into whatever the previous command on that tag left there. The
driver-private area is zeroed only when the tag set is allocated.
Reproduced with a test target that leaves a residual iterator on a tag
and then sends a C2HData for a WRITE_ZEROES command on the same tag:
BUG: KASAN: wild-memory-access in _copy_to_iter+0x642/0x1330
Write of size 512 at addr ffe728c2175dfa81 by task kworker/0:1H/103
CPU: 0 UID: 0 PID: 103 Comm: kworker/0:1H Not tainted 7.2.0-rc5-NVMETCP-gf5098b6bae76 #1 PREEMPT(lazy)
Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: nvme_tcp_wq nvme_tcp_io_work
Call Trace:
<TASK>
dump_stack_lvl+0x53/0x70
kasan_report+0xce/0x100
? _copy_to_iter+0x642/0x1330
kasan_check_range+0x105/0x1b0
__asan_memcpy+0x3c/0x60
_copy_to_iter+0x642/0x1330
? __pfx_sock_has_perm+0x10/0x10
? worker_thread+0x45b/0xd10
? __pfx__copy_to_iter+0x10/0x10
? _raw_spin_lock_bh+0x83/0xe0
? __pfx__raw_spin_lock_bh+0x10/0x10
__skb_datagram_iter+0xf3/0x820
? __pfx_simple_copy_to_iter+0x10/0x10
? __asan_memcpy+0x3c/0x60
? skb_copy_bits+0x58d/0x830
skb_copy_datagram_iter+0x37/0x120
nvme_tcp_recv_skb+0xa07/0x4320
? __pfx_nvme_tcp_recv_skb+0x10/0x10
__tcp_read_sock+0x1ab/0x810
? __pfx_nvme_tcp_recv_skb+0x10/0x10
? __pfx_lock_sock_nested+0x10/0x10
? __pfx___tcp_read_sock+0x10/0x10
nvme_tcp_try_recv+0x152/0x1e0
? __pfx_nvme_tcp_try_recv+0x10/0x10
? __pfx_mutex_unlock+0x10/0x10
nvme_tcp_io_work+0x1e4/0x6c0
? __schedule+0x181a/0x49f0
? __pfx_nvme_tcp_io_work+0x10/0x10
process_one_work+0x633/0x1030
Keep the blk_rq_payload_bytes() test and add req->data_len to it. The
old test is what rejects a C2HData naming a tag that is no longer in
flight, because blk_update_request() zeroes rq->__data_len on
completion; req->data_len and req->curr_bio are driver-private and
survive completion, so they cannot stand in for it. Setup initialises
the iterator only when both req->curr_bio and req->data_len are set, so
the gate now tests the same two.
CVE-2026-89479
Crítica · 9.8
11/09/2026
sctp: stop processing a packet once its association is deleted
In the Linux kernel, the following vulnerability has been resolved:
sctp: stop processing a packet once its association is deleted
sctp_endpoint_bh_rcv() looks the association up only when chunk->asoc is
NULL, and caches the result in chunk->asoc and chunk->transport without
taking a reference.
A packet that matches no association is handed to the endpoint, so a peer
can bundle COOKIE ECHO, SHUTDOWN and SHUTDOWN ACK in one packet. The
COOKIE ECHO creates the association, the SHUTDOWN chunk caches it, and
with the outqueue empty the SHUTDOWN ACK reaches sctp_sf_do_9_2_final(),
so the association and its transports are freed.
The endpoint loop has no counterpart to the asoc->base.dead check in
sctp_assoc_bh_rcv(). The next chunk writes to last_time_heard in the freed
transport and is then passed to sctp_do_sm() with the freed association.
The transport is freed through RCU, so this needs the packet to come off
the socket backlog, where the loop runs in task context.
The endpoint loop cannot do the same check: it holds no reference on the
association, so reading asoc->base.dead would itself be a use-after-free.
Mark the packet for discard in the command interpreter, just before it
deletes the association. That is also before sctp_inq_free() releases the
chunk on the association receive path.
sctp_sf_do_5_2_4_dupcook() issues SCTP_CMD_DELETE_TCB for the temporary
association, while the one the packet belongs to stays alive. A restarting
peer can bundle DATA behind its COOKIE ECHO, so compare against
chunk->asoc and leave that case alone.
CVE-2026-89478
Crítica · 9.8
11/09/2026
sctp: drop a chunk if its transport was removed
In the Linux kernel, the following vulnerability has been resolved:
sctp: drop a chunk if its transport was removed
sctp_rcv() resolves the transport once per packet and leaves it in
chunk->transport. The lookup reference, or the one sctp_add_backlog() takes
if the socket is owned by userspace, keeps it around until the chunk has
been processed.
An authenticated ASCONF DEL-IP can remove it in the meantime.
sctp_assoc_rm_peer() takes the transport out of the association and calls
sctp_transport_free(), which tags it dead and drops the reference the
association held. There is a window on both paths: the packet can sit on
the socket backlog, and on the direct path the lookup completes before
bh_lock_sock().
The DATA chunk in that packet puts the removed transport back into
asoc->peer.last_data_from. Once the packet is done that reference goes
away and the transport is freed by RCU, so the next delayed SACK carries
the pointer into the SACK chunk and sctp_outq_select_transport() reads the
freed transport's state.
Drop the chunk in sctp_inq_push(), next to the existing rcvr->dead check.
Both paths reach it with the association's socket lock held. The peer
retransmits it.
CVE-2026-89448
Crítica · 9.3
11/09/2026
iommu/vt-d: Force requesting ACS when tboot is enabled
In the Linux kernel, the following vulnerability has been resolved:
iommu/vt-d: Force requesting ACS when tboot is enabled
Currently the conditions of requesting ACS in detect_intel_iommu()
don't include tboot, leading to a possible misconfiguration with ACS
disabled (e.g. due to user opts) while iommu is later forced on by
tboot_force_iommu().
Fix it by checking tboot in detect_intel_iommu().
CVE-2026-81002
Crítica · 9.8
11/09/2026
xdp: fix zero-copy frame layout
In the Linux kernel, the following vulnerability has been resolved:
xdp: fix zero-copy frame layout
xdp_convert_zc_to_xdp_frame() clones an XSK packet into an order-0 page
and advertises PAGE_SIZE as its frame size. It allows the copied frame
to occupy the page tail needed by skb_shared_info and records zero
headroom even when metadata separates the frame header from packet data.
An AF_XDP zero-copy packet redirected through cpumap can therefore make
the skb overlap skb_shared_info or place it beyond the allocated page.
Limit the copied layout to SKB_WITH_OVERHEAD(PAGE_SIZE) and include the
metadata length in frame headroom. Redirect callers already handle a
NULL conversion result.
BUG: KASAN: slab-out-of-bounds in skb_gro_receive
Write of size 4 at addr ffff88800cf37004 by task cpumap/1/map:1/146
Call Trace:
skb_gro_receive (net/core/gro.c:174)
udp_gro_receive (net/ipv4/udp_offload.c:812)
inet_gro_receive (net/ipv4/af_inet.c:1539)
dev_gro_receive (net/core/gro.c:515)
gro_receive_skb (net/core/gro.c:633)
cpu_map_kthread_run (kernel/bpf/cpumap.c:395)
kthread (kernel/kthread.c:436)
ret_from_fork (arch/x86/kernel/process.c:164)
ret_from_fork_asm (arch/x86/entry/entry_64.S:255)
Kernel panic - not syncing: KASAN: panic_on_warn set ...