| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
ceph: do not repeat ceph_trim_dentries() if no progress possible
ceph_cap_reclaim_work() re-queues itself for as long as
ceph_trim_dentries() returns -EAGAIN, which happens whenever a lease
walk exhausts its `nr_to_scan` budget. This creates a busy loop that
consumes CPU without making any progress when there is nothing to
reclaim: with no cap pressure (`count==0`) and every scanned lease
still valid, each pass runs the full scan budget down to zero and
returns `-EAGAIN`, only to be queued again immediately.
The dir-lease walk made this worse. When `expire_dir_lease` is
`false` (i.e. we have no intention of reclaiming dir leases),
__dir_lease_check() returned `TOUCH` for every valid lease. `TOUCH`
moves the dentry to the tail of the list and resets `di->time` via
__dentry_dir_lease_touch(), so a walk over N valid leases pointlessly
rewrote the list, refreshed the timestamps (preventing them from ever
aging out) and always drained `nr_to_scan`, guaranteeing the `-EAGAIN`
requeue.
Fix this in three steps:
- Return `KEEP` instead of `TOUCH` when `expire_dir_lease` is
`false`. If we are not going to reclaim the lease, leave it in
place instead of churning the list and resetting its timestamp; the
walk then terminates naturally (or via `STOP` at the first fresh
lease).
- Only return `-EAGAIN` from the first (dentry-lease) walk when something
was actually freed. A full batch that frees nothing means retrying
the same list immediately is futile; fall through to the dir-lease
walk instead.
- After both walks, bail out with success (0) when nothing was freed
and there is no cap pressure (`count==0`). There is no reason to
keep retrying when we are not over the cap limit and made no
progress.
Under real cap pressure (`count>0`) the reclaim path is unchanged and
still retries via `-EAGAIN`.
Without this patch, I saw 500 ceph_trim_dentries() calls per second on
our web servers. This is very visible in `/proc/lock_stat` (5 minute
capture):
class name con-bounces contentions waittime-min waittime-max waittime-total waittime-avg acq-bounces acquisitions holdtime-min holdtime-max holdtime-total holdtime-avg
&mdsc->dentry_list_lock: 126180 128218 0.04 8063.44 15986965.20 124.69 1573354 5296812 0.04 8291.28 74164526.48 14.00
-----------------------
&mdsc->dentry_list_lock 111736 [<000000007b11e319>] __ceph_dentry_dir_lease_touch+0x7c/0xa8
&mdsc->dentry_list_lock 2631 [<0000000050597999>] __dentry_leases_walk+0x64/0x2c8
&mdsc->dentry_list_lock 3878 [<00000000c0022f62>] __ceph_dentry_lease_touch+0x5c/0xa8
&mdsc->dentry_list_lock 9973 [<000000002f27cb6f>] __dentry_lease_unlist+0x50/0xa0
-----------------------
&mdsc->dentry_list_lock 123621 [<0000000050597999>] __dentry_leases_walk+0x64/0x2c8
&mdsc->dentry_list_lock 1822 [<000000007b11e319>] __ceph_dentry_dir_lease_touch+0x7c/0xa8
&mdsc->dentry_list_lock 2720 [<000000002f27cb6f>] __dentry_lease_unlist+0x50/0xa0
&mdsc->dentry_list_lock 55 [<00000000c0022f62>] __ceph_dentry_lease_touch+0x5c/0xa8
With this patch:
class name con-bounces contentions waittime-min waittime-max waittime-total waittime-avg acq-bounces acquisitions holdtime-min holdtime-max holdtime-total holdtime-avg
&mdsc->dentry_list_lock: 1203 1215 0.16 408.88 33082.88 27.23 4320501 7357389 0.04 500.64 1961578.00 0.27
-----------------------
&mdsc->dentry_list_lock 1029 [<000000003c9aea8a>] __ceph_dentry_dir_lease_touch+0x7c/0xa8
&mdsc->dentry_list_lock 1
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: drop recovered reloc root refs on recovery failure
During relocation recovery, each fs root gets a reference to its relocation
root. If loading or adding a later root fails, or if the first transaction
commit fails, btrfs_recover_relocation() jumps to out_unset before
merge_reloc_roots() and clean_dirty_subvols().
put_reloc_control() drops the list-owned relocation root references, but it
does not clear fs_root->reloc_root or drop the references owned by those
pointers. Mount cleanup only drops them when BTRFS_FS_ERROR is set, so an
error such as -ENOMEM while processing a later root can leave references
behind.
Keep temporary references to the fs roots associated during recovery. On
failure, clear their reloc_root pointers and drop the corresponding
references. Once the first transaction commit succeeds, drop only the
temporary fs root references and let the normal merge and cleanup paths
handle the relocation roots.
Fault injection on a pending-relocation image confirmed the cleanup gap.
With an injected first-commit failure, 25 fs roots had reloc_root set with
fs_error=0. With this fix, the same failure path drops that count to 0
before mount fails. |
| In the Linux kernel, the following vulnerability has been resolved:
cifs: fix loff_t underflow in cifs_remap_file_range() when len == 0
With len == 0 (clone to EOF), the effective length is computed as:
len = src_inode->i_size - off;
If off > i_size, this is a negative loff_t, corrupting the ByteCount
in the FSCTL_DUPLICATE_EXTENTS_TO_FILE request and inverting the range
in filemap_write_and_wait_range(). The existing off >= i_size check
fires only after the ioctl has already been sent.
Snapshot i_size_read() once for both the bounds check and the length
calculation, eliminating the TOCTOU and 32-bit torn-read risk. Reject
off > src_size with -EINVAL. Treat off == src_size as a no-op,
consistent with __generic_remap_file_range_prep(). |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: clear setuid/setgid bit on write with cifsacl/modefromsid/posix extensions
When a file has the setuid or setgid bit set and is written to, the VFS
strips those bits and issues a setattr with ATTR_KILL_SUID/ATTR_KILL_SGID
together with an ATTR_MODE carrying the already-cleared mode.
Both cifs_setattr_unix() and cifs_setattr_nounix() unconditionally dropped
ATTR_MODE in that case:
/* skip mode change if it's just for clearing setuid/setgid */
if (attrs->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID))
attrs->ia_valid &= ~ATTR_MODE;
This is fine for the default mount, where the mode is only emulated via
the DOS read-only attribute and cannot represent the setuid/setgid bits
anyway. However, with the "cifsacl" or "modefromsid" mount options the
mode is stored on the server through an ACL (id_mode_to_cifs_acl()), with
the SMB3.1.1 POSIX extensions the mode is sent to the server directly,
and with the SMB1 Unix extensions (cifs_setattr_unix) the mode is sent
via CIFSSMBUnixSetPathInfo(). In all those cases dropping ATTR_MODE means
the cleared mode is never pushed to the server, so the setuid/setgid bit
survives the write.
This is a security issue: on local filesystems the setuid bit is stripped
when a file is written, but over these cifs.ko mounts the bit persists on
the server, potentially allowing an unexpected privilege escalation on
subsequent execution.
Fix this in two places:
1. cifs_setattr_nounix(): only take the "skip mode change" shortcut
when the mode is emulated via the DOS read-only attribute (i.e.
neither cifsacl/modefromsid nor the SMB3.1.1 POSIX extensions are
in effect), so that the cleared mode is propagated to the server
in the ACL / POSIX cases.
2. cifs_setattr_unix(): this function is only called when Unix
extensions are in effect, so the mode is always stored on the
server. Remove the shortcut entirely so that the cleared mode is
always pushed. |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix OOB read/write from unvalidated DataOffset in coalesce_t2()
coalesce_t2() computes data pointers directly from server-supplied
DataOffset fields with no validation against buffer bounds:
data_area_of_tgt = (char *)&pSMBt->hdr.Protocol +
get_unaligned_le16(&pSMBt->t2_rsp.DataOffset);
data_area_of_src = (char *)&pSMBs->hdr.Protocol +
get_unaligned_le16(&pSMBs->t2_rsp.DataOffset);
data_area_of_tgt += total_in_tgt;
...
memcpy(data_area_of_tgt, data_area_of_src, total_in_src);
A small DataOffset can push a pointer below the actual byte area,
overwriting header fields; a large one can push it past the buffer
end, causing out-of-bounds heap reads (source) or writes (target).
The BCC overflow guard does not prevent this: BCC reflects how much
data is present, while DataOffset controls where in the buffer it
starts.
The "validate target area" comment present since the function was
first written in 2005 was a placeholder that was never implemented.
Add lower- and upper-bound checks for both data pointers before the
memcpy, and before any target header fields are modified. |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: reject a tree connect response whose byte count is too small
CIFSTCon() bounds its strnlen() over the byte area with the server's
ByteCount minus two, which for ByteCount 0 or 1 goes negative as an int
and converts to a huge size_t. The later subtraction wraps the __u16
bytes_left, and that is what bounds cifs_strndup_from_utf16(): a bound of
up to 65535 against a ~16 KB cifs_req_poolp object runs off the end of the
slab object, and the bytes reach userspace through tcon->nativeFileSystem
in /proc/fs/cifs/DebugData.
Reject a byte area too small for what the parser consumes. Two bytes is
the least it can consume, and no conformant response carries fewer. The
new trace point is the 129th smb_eio_trace entry, which __mode(byte)
cannot represent, so the attribute goes with it. |
| In the Linux kernel, the following vulnerability has been resolved:
HID: sony: fix UAF of ghl_poke_timer / ghl_urb at driver unbind
For GHL (Guitar Hero Live) dongles, sony_probe() arms a periodic timer:
ghl_magic_poke() (the timer callback) submits sc->ghl_urb, and the URB
completion ghl_magic_poke_cb() re-arms the timer with mod_timer().
sony_remove() drained the timer with timer_delete_sync() and then freed
the URB with usb_free_urb():
timer_delete_sync(&sc->ghl_poke_timer);
usb_free_urb(sc->ghl_urb);
timer_delete_sync() does not block re-arming, and while the URB is in
flight the timer is not pending, so the sync delete is a no-op. A URB
completion that runs after the delete re-arms the timer, and usb_free_urb()
only drops a reference -- it does not kill an in-flight URB. sc is
allocated with devm_kzalloc() and freed once sony_remove() returns, so the
re-armed ghl_poke_timer (embedded in sc) then fires on freed memory, a
use-after-free from timer softirq. This is a disconnect/rmmod race.
Poison the URB first, then shut the timer down, before freeing the URB.
usb_poison_urb() kills any in-flight URB and permanently rejects further
submissions, so a poke timer that is still pending cannot re-submit the
URB from ghl_magic_poke() in the window before timer_shutdown_sync() runs.
usb_kill_urb() would not suffice: it only cancels the in-flight URB and
leaves it submittable once it returns, so the pending timer could
re-submit it and put a fresh URB in flight over the freed sc.
timer_shutdown_sync() then drains any last callback and blocks re-arming.
The probe error path is unaffected: it is only reached before the timer
is armed.
Reproduced under KASAN on next-20260710 via dummy_hcd + raw-gadget
emulation of the GHL PS4 dongle (VID 0x1430 / PID 0x07bb): hid-sony binds
and arms the poke timer, the poke URB is held in flight, the driver is
unbound (freeing sc), then the URB is released. The completion re-arms the
timer on the freed sc, and the re-armed timer fires ~8 s later:
BUG: KASAN: slab-use-after-free in ghl_magic_poke+0x98/0xb0
Read of size 8 at addr ffff88810b02fd50 by task swapper/0/0
ghl_magic_poke+0x98/0xb0
call_timer_fn+0x35/0x2b0
__run_timers+0x69c/0x9a0
run_timer_softirq+0x173/0x2a0
Allocated by task 169: sony_probe
Freed by task 338: devres_release_group <- hid_device_remove (sony_remove)
Found by 0sec (https://0sec.ai) using automated source analysis. |
| In the Linux kernel, the following vulnerability has been resolved:
HID: mcp2221: clear rxbuf after I2C/SMBus transfer completes
mcp_i2c_smbus_read() stores the caller-supplied buffer pointer in
mcp->rxbuf for the duration of a transfer but never clears it when the
transfer finishes or times out. Once the caller frees or reuses the
buffer, mcp->rxbuf becomes a dangling pointer. A delayed or spurious
MCP2221_I2C_GET_DATA report can then drive mcp2221_raw_event() to
memcpy device data into the freed memory, causing a write
use-after-free.
Route all return paths through a single exit point that clears
mcp->rxbuf and mcp->rxbuf_size, so that the existing !mcp->rxbuf guard
in the raw_event handler can reject any report arriving after the
transfer has ended. |
| In the Linux kernel, the following vulnerability has been resolved:
ext2: Fix lost inode updates for IS_SYNC inodes
ext2_setsize() and ext2_xattr_set2() had a construct like:
if (IS_SYNC(inode)) {
sync_inode_metadata(inode, 1);
} else {
mark_inode_dirty(inode);
}
which leads to lost inode updates for IS_SYNC inodes because
sync_inode_metadata() does anything only if the inode is already dirty
and hence inode updates may be simply lost. Fix the problem by
unconditionally marking the inode dirty and *then* call
sync_inode_metadata(). |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Disable preemption in __bpf_get_stack
get_perf_callchain() returns a per-CPU perf_callchain_entry buffer and
releases its recursion slot via put_callchain_entry() before returning,
so nothing keeps the entry reserved while __bpf_get_stack() consumes
it below.
A preemptible BPF program (e.g. a non-sleepable raw tracepoint program
on a PREEMPT kernel, which runs under migrate_disable() but not
preempt_disable()) can be scheduled out between obtaining the entry
and the copy. Another task scheduled on the same CPU then reuses the
same per-CPU buffer and overwrites trace->nr with a larger value.
copy_len is then computed from the inflated trace->nr and can exceed
the caller's buffer, causing an out-of-bounds write in the memcpy()
and in the build_id path.
The rcu_read_lock() taken here alone does not prevent this. It is
only taken on the may_fault path, and under CONFIG_PREEMPT_RCU it does
not disable preemption; it merely keeps perf's callchain buffer array
alive (freed via call_rcu()) and does nothing to stop another task
from reusing the entry.
Disable preemption around obtaining the callchain entry and copying
it into the caller's buffer, so the entry cannot be reused underneath
us and trace->nr stays bounded by max_depth. Build ID resolution may
fault and is therefore deferred until after preemption is re-enabled;
by then the instruction pointers have already been copied into buf,
so it operates only on that private copy. Note, preempt_disable() also
subsumes the buffer-lifetime guarantee the rcu_read_lock() provided,
since a preempt-disabled section is an RCU read-side critical section
for the callchain buffers' call_rcu() reclaim.
[ changed Fixes: commit ] |
| In the Linux kernel, the following vulnerability has been resolved:
dm array: validate array block headers on read
array_block_check() validates blocknr and csum and nothing else, while
node_check(), next to it, has bounded the structural fields since both
were written. dm_array_cursor_next() takes its loop bound from the
on-disk nr_entries and element_at() is unguarded pointer arithmetic, so
a count larger than the block holds keeps the cursor in one block while
the index grows past it and the read walks off the dm-bufio buffer --
dm_cache_load_mappings() drives it once per cache block at activation.
Check the header against itself: reject a zero value_size, require
max_entries to equal calc_max_entries() for that value_size and block
size, and require nr_entries to fit. Equality rather than an upper bound,
since a count below the real capacity trips BUG_ON() in fill_ablock() and
trim_ablock(). Metadata dm-array writes satisfies all three. |
| In the Linux kernel, the following vulnerability has been resolved:
ip: orphan prefetched skbs before multicast forwarding
IPv4 and IPv6 input preserve an skb->sk association installed by
bpf_sk_assign() so that local delivery can use the selected socket under
RCU. Both address families can also prefetch a socket in UDP early demux.
In both paths (BPF and UDP early demux) a reference is not guaranteed to
be held on the socket.
When a multicast packet is not locally deliverable, IPv6 hands the
original skb to ip6_mr_input(). IPv4's ip_mr_input() similarly keeps the
original skb when local delivery is not needed. Either path can put the
skb on an unresolved multicast route queue or forward it after the
receive-side RCU section ends.
After the prefetched socket is destroyed, a later skb free invokes
sock_pfree() and dereferences the stale skb->sk. Orphan the skb before
each non-local multicast forwarding path. Local delivery retains the
original skb; the existing skb_clone() calls provide multicast forwarding
with a socket-free clone. |
| In the Linux kernel, the following vulnerability has been resolved:
ipv6: rpl: fix NULL dereference of idev in ipv6_rpl_srh_rcv()
ipv6_rpl_srh_rcv() dereferences idev from __in6_dev_get() without a NULL
check when reading idev->cnf.rpl_seg_enabled.
When the device's MTU drops below IPV6_MIN_MTU, addrconf_ifdown() clears
dev->ip6_ptr through RCU_INIT_POINTER(). A packet that passed the idev
check in ip6_rcv_core() can then reach ipv6_rpl_srh_rcv() with
dev->ip6_ptr already NULL.
Reproduced by flooding the receiving interface with ping6 traffic while
flapping its MTU between 1500 and 1200:
BUG: KASAN: null-ptr-deref in ipv6_rpl_srh_rcv+0xb3/0x1070
Read of size 4 at addr 00000000000006b4 by task ping6/394
CPU: 2 UID: 0 PID: 394 Comm: ping6 Not tainted 7.2.0-rc7-micro-vm-dev-00095-g24ef02f934ee #240 PREEMPT(full)
Call Trace:
<IRQ>
kasan_report+0xc6/0x100
ipv6_rpl_srh_rcv+0xb3/0x1070
ip6_protocol_deliver_rcu+0x759/0x9a0
ip6_input_finish+0xa8/0x1b0
ip6_input+0xe1/0x490
ipv6_rcv+0x33d/0x460
__netif_receive_skb_one_core+0xd6/0x130
process_backlog+0x2cc/0xa00
__napi_poll.constprop.0+0x56/0x270
net_rx_action+0x327/0x730
handle_softirqs+0x11e/0x630
do_softirq+0xb3/0xf0
</IRQ>
Both ipv6_rpl_srh_rcv() and ipv6_srh_rcv() are called only from
ipv6_rthdr_rcv(), which already has an idev lookup.
Fix the NULL dereference on the RPL path by checking idev in
ipv6_rthdr_rcv(), before it calls either function. The callees take idev as
an argument and no longer call __in6_dev_get(), so the packet is now
dropped in one place, with SKB_DROP_REASON_IPV6DISABLED on both paths. |
| In the Linux kernel, the following vulnerability has been resolved:
nouveau/gem: reserve the bo in the info ioctl around the vma lookup
In the non-uvmm path, there could be a race between the info lookup
finding the vma, and the gem close path closing the vma leading
to a use-after-free.
Spotted with the help of Opus 4.6. |
| 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: 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: reject duplicate CREDS_VALUE options
gssx_dec_option_array() walks the wire-supplied option array and, for
every entry whose name matches CREDS_VALUE, calls
gssx_dec_linux_creds() on the same struct svc_cred. That helper
unconditionally installs a fresh groups_alloc() result into
creds->cr_group_info without releasing whatever pointer was already
there:
for (i = 0; i < count; i++) {
... decode name ...
if (length == sizeof(CREDS_VALUE) &&
memcmp(p, CREDS_VALUE, sizeof(CREDS_VALUE)) == 0) {
err = gssx_dec_linux_creds(xdr, creds);
...
}
}
A reply that carries two CREDS_VALUE entries therefore overwrites
cr_group_info on the second iteration and orphans the group_info
allocated by the first call. The earlier free_creds path only
releases the last cr_group_info via free_svc_cred(), so the first
allocation's refcount stays at one and its kvmalloc-backed storage
is leaked. No in-tree caller of gssp_accept_sec_context_upcall()
expects more than one CREDS_VALUE per reply.
Fix by tracking whether a CREDS_VALUE option has already been
decoded and returning -EINVAL on any subsequent match, so the
free_creds path releases the single group_info that was installed. |
| 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:
svcrdma: Reject connection when transport allocation fails
handle_connect_req() returns without action when
svc_rdma_create_xprt() fails to allocate the new transport.
The CM core returns 0 for CONNECT_REQUEST events, so it does
not destroy the new rdma_cm_id. Each allocation failure under
memory pressure leaks one rdma_cm_id, and a remote peer driving
connection attempts can amplify this.
Reject the connection by returning a non-zero status from the
CM event handler, which tells the CM core to destroy the
orphaned cm_id. |
