| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| 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; |
| In the Linux kernel, the following vulnerability has been resolved:
SUNRPC: Check svc pool percpu counter allocation
__svc_create() initializes three per-pool percpu_counter stats and
ignores every return value. On SMP, percpu_counter_init() fails when
__alloc_percpu_gfp() cannot satisfy the allocation, leaving the failed
counter with fbc->counters == NULL and its embedded raw_spinlock_t,
list_head, and count never initialized. __svc_create() returns the
half-constructed svc_serv to nfsd, lockd, or the NFS callback service
anyway.
Once that service is live, the hot-path increments in
svc_xprt_enqueue(), svc_handle_xprt(), and
svc_pool_wake_idle_thread() reach a counter whose backing pointer is
NULL. The pointer is a per-cpu offset, so the access does not fault:
it resolves to offset zero of the current CPU's per-cpu area and
silently corrupts whatever variable lives there. A
/proc/fs/nfsd/pool_stats read walks the same NULL per-cpu storage and
returns garbage, and on CONFIG_DEBUG_SPINLOCK or lockdep it splats on
the never-initialized lock.
Creating the broken service requires a percpu allocation failure during
RPC server startup, so it is reachable only by a local administrator
under memory pressure or fault injection; a remote peer cannot induce
the bad state on its own.
Check each percpu_counter_init() return value in __svc_create() and
fail when an allocation fails, unwinding the counters already set up
in the current pool and in every pool initialized before it. A
discrete percpu_counter_destroy() per counter at teardown frees each
per-cpu allocation exactly once. |
| 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. |
| In the Linux kernel, the following vulnerability has been resolved:
sunrpc: defer rq_argp and rq_resp free until after RCU grace period
svc_rqst_free() frees rqstp->rq_argp and rqstp->rq_resp synchronously
via kfree(), but defers the rqstp struct free via kfree_rcu(). After
svc_exit_thread() calls list_del_rcu() and svc_rqst_free(), there is
a window where RCU readers that started before list_del_rcu() can still
traverse the thread list and find the rqstp. These readers (e.g.
nfsd_nl_rpc_status_get_dumpit()) dereference rqstp->rq_argp, which has
already been freed — a use-after-free.
Fix this by moving the kfree of rq_argp and rq_resp into an explicit
call_rcu() callback alongside the struct free. Resources not accessed
by RCU readers (bvec, buffer pages, scratch folio, auth_data) remain
synchronously freed. |
| In the Linux kernel, the following vulnerability has been resolved:
SUNRPC: fix gssx_dec_option_array error path bugs
Four coupled defects in the gssx XDR option-array decoder make the
error paths unsafe: a NULL deref in the caller, a refcount leak on
the decoded group_info, and a latent use-after-free that the leak
fix would otherwise expose.
gssx_dec_option_array() sets oa->count = 1 before allocating
oa->data. If that allocation fails, -ENOMEM is returned with
oa->count == 1 and oa->data == NULL. All other error paths jump
to free_oa: which frees oa->data and NULLs it but also leaves
oa->count == 1. The caller trusts the count:
gssp_accept_sec_context_upcall()
gssx_dec_accept_sec_context()
gssx_dec_option_array() /* fails, count=1 data=NULL */
data = res.options.data[0].value /* NULL deref */
Independently, free_creds: releases the partially decoded svc_cred
with a bare kfree(creds). gssx_dec_linux_creds() installs a
groups_alloc() result into creds->cr_group_info; that object is
kvmalloc-backed and refcounted, and only put_group_info() reaches
kvfree(). A plain kfree(creds) drops the wrapper and leaks the
group_info allocation.
The natural fix for the leak is to call free_svc_cred(creds) before
kfree(creds), but free_svc_cred() invokes put_group_info() on
creds->cr_group_info unconditionally when non-NULL. The existing
out_free_groups: path in gssx_dec_linux_creds() already called
groups_free() on that pointer without clearing it, so once
free_svc_cred() is wired in, the subsequent put_group_info() would
touch freed memory.
Fix all four together:
- Move the oa->count = 1 assignment below the oa->data allocation
so it is never set when oa->data is NULL.
- Reset oa->count to 0 at free_oa: so count and data stay
coherent and the caller sees an empty option array.
- Call free_svc_cred(creds) before kfree(creds) at free_creds:
so the refcounted cr_group_info is released. free_svc_cred()
either NULL-guards each field explicitly (cr_group_info has
an if() check) or delegates to a helper that is NULL-safe
itself (kfree for the string fields, gss_mech_put() which
guards with if(gm) at gss_mech_switch.c:342), so it is safe
to call on a partially decoded svc_cred where only
cr_uid/cr_gid/cr_group_info have been written and everything
else is zero from kzalloc.
- In gssx_dec_linux_creds()'s out_free_groups: path, release
cr_group_info with put_group_info() rather than groups_free()
so the teardown matches free_svc_cred()'s refcount-aware path,
and clear the pointer so a later free_svc_cred() on the same
creds does not release it a second time. |
| In the Linux kernel, the following vulnerability has been resolved:
sunrpc: fix use-after-free in __rpc_clnt_handle_event and __rpc_clnt_remove_pipedir
Normal client creation goes through rpc_setup_pipedir(), which records
clnt->pipefs_sb, but the mount-event path in __rpc_clnt_handle_event()
calls rpc_setup_pipedir_sb() directly and never refreshes that field.
The umount path also removes the directory without clearing
clnt->pipefs_sb.
After a late pipefs mount or any remount, rpc_clnt_remove_pipedir()
compares the current superblock against a stale pipefs_sb pointer and
skips cleanup, leaving pipefs dentries whose inode private data still
points at a freed rpc_clnt, leading to a potential use-after-free during
subsequent rpc_info_open() or rpc_show_info() calls.
Fix this by properly updating clnt->pipefs_sb upon mount events and
clearing it during unmount or failure paths. |
| 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. |
| 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"). |
| In the Linux kernel, the following vulnerability has been resolved:
sunrpc: init gssp_lock before publishing proc entry
create_use_gss_proxy_proc_entry() publishes /proc/net/rpc/use-gss-proxy
via proc_create_data() before init_gssp_clnt() runs mutex_init() on
sn->gssp_lock. Once the dentry is linked under proc_subdir_lock it is
immediately reachable from userspace, so a write that lands in the
window drives set_gssp_clnt() into mutex_lock() on a zero-initialized
struct mutex.
create_use_gss_proxy_proc_entry(net)
proc_create_data("use-gss-proxy", ...) /* dentry live */
init_gssp_clnt(sn)
mutex_init(&sn->gssp_lock) /* too late */
write_gssp()
set_gssp_clnt(net)
mutex_lock(&sn->gssp_lock) /* uninitialized */
gssp_rpc_create(...)
sn->gssp_clnt = clnt
mutex_unlock(&sn->gssp_lock)
The window spans only the two statements between proc_create_data()
returning and init_gssp_clnt(), so a writer reaches it only if the
registering thread is preempted there while another task is already
opening the freshly published file. register_pernet_subsys() runs in
preemptible context under pernet_ops_rwsem, so that preemption is
possible, and the window widens on auth_rpcgss module load, when the
proc entry is created for every live net namespace whose tasks are
already running. A writer that wins the race locks a zero-filled
struct mutex. On CONFIG_DEBUG_MUTEXES the missing magic value trips a
"lock used without init" splat; on a production kernel the fast path
acquires the lock via CMPXCHG(owner, 0, current). In the latter case
a second writer that arrives before init_gssp_clnt() re-zeroes owner
can enter set_gssp_clnt() concurrently, shut down the first writer's
clnt while it is still in use, and leak the loser's clnt.
Fix by initializing sn->gssp_lock in sunrpc_init_net() so its lifetime
matches the sunrpc_net it lives in. sn->gssp_clnt is already NULL from
the kzalloc that backs net_generic storage, so the lazy helper is no
longer needed; drop init_gssp_clnt(), its prototype, and the call from
create_use_gss_proxy_proc_entry(). sunrpc.ko is a build-time
dependency of auth_rpcgss.ko, so sunrpc_init_net() has always run on
every netns before any auth_gss pernet init can publish the proc
entry. |
| 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. |
| 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. |
| 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. |
| In the Linux kernel, the following vulnerability has been resolved:
svcrdma: Clear sc_cm_id when ADDR_CHANGE replacement fails
When svc_rdma_listen_handler() handles RDMA_CM_EVENT_ADDR_CHANGE,
it creates a replacement listener cm_id and returns 1, telling
the CM core to destroy the old one. If the replacement allocation
fails, sc_cm_id still points at the old cm_id that the CM core is
about to destroy. Any subsequent dereference of sc_cm_id --
such as svc_rdma_detach()'s rdma_disconnect() call -- is a
use-after-free.
NULL sc_cm_id on the failure path and guard svc_rdma_detach()'s
rdma_disconnect() call against NULL so that the listener can
be torn down safely when the server shuts down. |
| 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. |
| 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. |
| In the Linux kernel, the following vulnerability has been resolved:
svcrdma: Reject oversized Read segments at decode time
The RPC/RDMA Read list decoder stores wire-supplied segment
lengths without validation. xdr_count_read_segments() checks
4-byte alignment for non-zero position values but does not
cap the segment length.
An oversized rs_length reaches svc_rdma_build_read_segment(),
which derives nr_bvec from it and can drive a large dynamic
bvec allocation before verifying that enough rq_pages remain.
If the post-allocation page-overrun guard fires, the freshly
acquired rw context is not returned, leaking the resource.
Reject any segment whose length exceeds the receive context's
page budget during Read list decoding, consistent with how
xdr_check_write_chunk() bounds Write segment counts against
rc_maxpages. Also return the rw context on the existing
post-allocation overrun path in svc_rdma_build_read_segment(),
keeping that defensive guard balanced. |
| In the Linux kernel, the following vulnerability has been resolved:
svcrdma: Reject Read lists that exceed the page budget
Individual Read segment lengths are validated at decode time, but
nothing prevents a requester from sending multiple segments whose
cumulative length exceeds the rq_pages array budget. When one
segment fills the page array exactly, the runtime guard in
svc_rdma_build_read_segment() is bypassed because len reaches zero.
A subsequent segment then accesses the NULL sentinel slot at
rq_pages[rq_maxpages], resulting in a NULL pointer dereference during
DMA mapping.
Accumulate pages across all Read segments and reject the message at
decode time when the total would overflow the page budget. |
| In the Linux kernel, the following vulnerability has been resolved:
svcrdma: Use svc_xprt_put to free listener on create failure
svc_rdma_create() calls kfree(cma_xprt) when
svc_rdma_create_listen_id() fails. svc_xprt_init() has already
acquired a net namespace reference via get_net_track(); kfree
bypasses svc_xprt_free() which releases it.
Replace the kfree() with svc_xprt_put() so the kref_init birth
reference drops to zero and svc_xprt_free() dispatches
svc_rdma_free() to clean up properly. sc_cm_id is still NULL
at that point; the preceding patch added the necessary NULL
guard in svc_rdma_free().
svc_xprt_free() also drops the module reference via
module_put(), but the caller _svc_xprt_create() does the same
on xpo_create failure, double-putting the single
try_module_get() it acquired. Take a compensating
__module_get() before the svc_xprt_put() to keep the count
balanced, matching the convention in svc_rdma_accept()'s error
path. |
| 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. |
| In the Linux kernel, the following vulnerability has been resolved:
udf: reject VAT indexes equal to the entry count
UDF 1.50 virtual partition mapping uses the VAT as an array of physical
block mappings. s_num_entries stores the number of entries in that array,
not the highest valid index. The valid VAT indexes are therefore below
s_num_entries.
udf_get_pblock_virt15() currently rejects only indexes greater than
s_num_entries. A crafted image can request index s_num_entries, pass the
bounds check, and make the kernel read one entry past the allocated VAT table.
Change the check to reject block >= s_num_entries, so the count is handled as
an exclusive upper bound.
A crafted UDF image reproduced this on origin/master commit
0e35b9b6ec0ffcc5e23cbdec09f5c622ad532b53 with a KASAN slab-out-of-bounds
report in udf_get_pblock_virt15().
Trail of Bits has a reproducer that triggers kernel panic demonstrating the bug, and can share it if needed. |
