| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
libceph: bound pg_{temp,upmap,upmap_items} length to CEPH_PG_MAX_SIZE
__decode_pg_temp() decodes an user-controlled length but only rejects
values large enough to overflow the allocation; it does not bound it to
CEPH_PG_MAX_SIZE. The helper backs both pg_temp and pg_upmap decoding, and
apply_upmap()/get_temp_osds() later copy the decoded list into the fixed-size
on-stack array struct ceph_osds.osds[CEPH_PG_MAX_SIZE]. A monitor that sends
an OSDMap with a pg_temp/pg_upmap entry longer than 32 thus causes a stack
out-of-bounds write.
An OSD set for a single PG can never exceed CEPH_PG_MAX_SIZE, so reject longer
entries at decode time. The bound is well below the old overflow threshold, so
it also covers the allocation-size overflow the previous check guarded against.
BUG: KASAN: stack-out-of-bounds in ceph_pg_to_up_acting_osds
Write of size 4 ... by task exploit
kasan_report (mm/kasan/report.c:595)
ceph_pg_to_up_acting_osds (net/ceph/osdmap.c:2617 net/ceph/osdmap.c:2833)
calc_target (net/ceph/osd_client.c:1638)
__submit_request (net/ceph/osd_client.c:2394)
ceph_osdc_start_request (net/ceph/osd_client.c:2490)
ceph_osdc_call (net/ceph/osd_client.c:5164)
rbd_dev_image_probe (drivers/block/rbd.c:6899)
do_rbd_add (drivers/block/rbd.c:7138)
...
kernel BUG at net/ceph/osdmap.c:2670!
[ idryomov: do the same in __decode_pg_upmap_items() ] |
| In the Linux kernel, the following vulnerability has been resolved:
fs/super: fix emergency thaw double-unlock of s_umount
do_thaw_all() iterates over all superblocks via __iterate_supers()
with SUPER_ITER_EXCL, which acquires s_umount exclusively before
calling the callback and releases it afterwards. However, the
callback do_thaw_all_callback() calls thaw_super_locked() which
unconditionally releases s_umount on every code path. This results
in a second unlock attempt in __iterate_supers() that corrupts the
rwsem state, triggering a DEBUG_RWSEMS warning:
[ 182.601148] sysrq: Emergency Thaw of all frozen filesystems
[ 182.601865] ------------[ cut here ]------------
[ 182.602375] DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)): count = 0x0, magic = 0xffff99b1011e5870, owner = 0x0, curr 0xffff99b101b06c80, list not empty
[ 182.603817] WARNING: kernel/locking/rwsem.c:1412 at up_write+0xa3/0x170, CPU#2: kworker/2:1/53
[ 182.604578] Modules linked in:
[ 182.604864] CPU: 2 UID: 0 PID: 53 Comm: kworker/2:1 Not tainted 7.2.0-rc4-00001-gbd3bd93ea98a-dirty #4 PREEMPT(lazy)
[ 182.605711] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1kylin1 04/01/2014
[ 182.606417] Workqueue: events do_thaw_all
[ 182.606750] RIP: 0010:up_write+0xaf/0x170
[ 182.607076] Code: 19 3a 92 48 0f 44 c2 48 8b 55 08 48 8b 55 00 4c 8b 45 08 48 8b 55 00 48 8d 3d ad 91 e0 01 48 8b 4d 20 50 48 c7 c6 f0 8c 26 92 <67> 48 0f b9 3a e8 d7 93 4e 00 58 eb 81 48 83 7f 18 00 48 c7 c2 8d
[ 182.608563] RSP: 0018:ffffb670001d7e08 EFLAGS: 00010246
[ 182.609007] RAX: ffffffff92349e8d RBX: 0000000000000000 RCX: ffff99b1011e5870
[ 182.609595] RDX: 0000000000000000 RSI: ffffffff92268cf0 RDI: ffffffff92914d10
[ 182.610283] RBP: ffff99b1011e5870 R08: 0000000000000000 R09: ffff99b101b06c80
[ 182.610847] R10: ffff99b10139a808 R11: fefefefefefefeff R12: 0000000000000000
[ 182.611414] R13: ffffffff90cf74d0 R14: 0000000000000000 R15: ffff99b1011e5800
[ 182.612009] FS: 0000000000000000(0000) GS:ffff99b1eaaee000(0000) knlGS:0000000000000000
[ 182.612670] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 182.613146] CR2: 00000000005c631c CR3: 00000000013ee000 CR4: 00000000000006f0
[ 182.613722] Call Trace:
[ 182.613946] <TASK>
[ 182.614130] __iterate_supers+0x128/0x150
[ 182.614463] do_thaw_all+0x1b/0x30
[ 182.614759] process_scheduled_works+0xbb/0x3f0
[ 182.615150] ? __pfx_worker_thread+0x10/0x10
[ 182.615499] worker_thread+0x129/0x270
[ 182.615816] ? __pfx_worker_thread+0x10/0x10
[ 182.616201] kthread+0xe2/0x120
[ 182.616469] ? __pfx_kthread+0x10/0x10
[ 182.616792] ret_from_fork+0x15b/0x240
[ 182.617115] ? __pfx_kthread+0x10/0x10
[ 182.617426] ret_from_fork_asm+0x1a/0x30
[ 182.617761] </TASK>
[ 182.617968] ---[ end trace 0000000000000000 ]---
[ 182.618412] Emergency Thaw complete
Fix this by switching to SUPER_ITER_UNLOCKED and acquiring s_umount
in the callback via super_lock_excl() before calling
thaw_super_locked(). This matches the locking pattern expected by
thaw_super_locked() and eliminates the double unlock.
While at it, remove the dead 'return;' at the end of
do_thaw_all_callback(). |
| In the Linux kernel, the following vulnerability has been resolved:
ftrace: Add global mutex to serialize trace_parser access
In ftrace, the trace_parser structure is allocated and initialized when
a trace file is opened, and is subsequently used across write and release
handlers to parse user input.
The affected handler paths and their specific functions are:
- Open paths: ftrace_regex_open(), ftrace_graph_open()
- Write paths: ftrace_regex_write(), ftrace_graph_write()
- Release paths: ftrace_regex_release(), ftrace_graph_release()
If userspace opens a trace file descriptor and shares it across multiple
threads, concurrent write calls will race on the parser's internal state,
specifically the 'idx', 'cont', and 'buffer' fields, leading to corrupted
input or undefined behavior.
Fix this by adding a global mutex, parser_lock, to serialize all access
to trace_parser across write and release paths, preventing concurrent
corruption of parser state. |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: serialize qdisc_rtab_list against concurrent get/put
qdisc_get_rtab() and qdisc_put_rtab() mutate the process-global singly
linked list qdisc_rtab_list and a plain non-atomic 'int refcnt' with no
lock. This was only safe because every caller historically held the RTNL
mutex, which serialized all rate-table lookups, inserts and frees.
That invariant no longer holds. cls_flower sets
TCF_PROTO_OPS_DOIT_UNLOCKED, so tc_new_tfilter() keeps rtnl_held == false
for it and sets TCA_ACT_FLAGS_NO_RTNL. That flag propagates through
tcf_exts_validate_ex() -> tcf_action_init() -> tcf_action_init_1() ->
tcf_police_init(), which calls qdisc_get_rtab()/qdisc_put_rtab() with the
RTNL mutex NOT held. Two RTM_NEWTFILTER requests on different CPUs, each
adding a flower filter with a police action carrying the same rate, then
race on qdisc_rtab_list and on the non-atomic refcnt, leading to a
use-after-free / double-free of the kmalloc-2k struct qdisc_rate_table.
qdisc_rtab_list is a single global (not per-netns), so the corrupted
object is shared system-wide.
BUG: KASAN: slab-use-after-free in qdisc_put_rtab+0x12f/0x160
qdisc_put_rtab+0x12f/0x160
tcf_police_init+0xda9/0x1590
tcf_action_init_1+0x460/0x6b0
tcf_action_init+0x439/0xa40
tcf_exts_validate_ex+0x42d/0x550
fl_change+0xddd/0x7da0
tc_new_tfilter+0xaa7/0x2420
rtnetlink_rcv_msg+0x95e/0xe90
which belongs to the cache kmalloc-2k of size 2048
Protect qdisc_rtab_list and the refcount with a dedicated spinlock. The
(sleeping, GFP_KERNEL) allocation in qdisc_get_rtab() is performed before
taking the lock; if a concurrent inserter added an identical table in the
meantime the freshly allocated one is freed under the lock, so no
duplicate is leaked. qdisc_put_rtab() now decrements the refcount and
unlinks under the same lock. |
| In the Linux kernel, the following vulnerability has been resolved:
net: gro: fix double aggregation of flush-marked skbs
Commit 0ab03f353d36 ("net-gro: Fix GRO flush when receiving a GSO
packet.") added a flush check to skb_gro_receive(), but
skb_gro_receive_list() lacks the same validation.
As a result, packets marked with NAPI_GRO_CB(skb)->flush may still be
re-aggregated.
This allows already-GRO'd packets with existing frag_list to be
re-aggregated into a new GRO session, corrupting the frag_list chain
structure. When skb_segment() attempts to unpack these malformed packets,
it encounters invalid state and triggers a kernel panic.
Scenario (Tethering/Device forwarding):
1. Driver: Generated aggregated packet P1 via LRO with frag_list
2. Dev A: Receives aggregated fraglist packet and flush flag set
3. Dev A: Re-enters GRO, skb_gro_receive_list() is called
4. Missing flush check allows re-aggregation despite flush flag
5. Frag_list chain becomes corrupted (loops or dangling refs)
6. Dev B: TX path calls skb_segment(), crashes on corrupted frag_list
Root cause in skb_segment():
The check at line ~4891:
if (hsize <= 0 && i >= nfrags && skb_headlen(list_skb) &&
(skb_headlen(list_skb) == len || sg)) {
When frag_list is corrupted by double aggregation, when list_skb is
a NULL pointer from skb->next, skb_headlen(list_skb) dereference
NULL/corrupted pointers occurs.
Call Trace:
skb_headlen(NULL skb)
skb_segment
tcp_gso_segment
tcp4_gso_segment
inet_gso_segment
skb_mac_gso_segment
__skb_gso_segment
skb_gso_segment
validate_xmit_skb
validate_xmit_skb_list
sch_direct_xmit
qdisc_restart
__qdisc_run
qdisc_run
net_tx_action
Fix: Add NAPI_GRO_CB(skb)->flush validation to the early-return check in
skb_gro_receive_list(), matching the defensive programming pattern of
skb_gro_receive(). |
| In the Linux kernel, the following vulnerability has been resolved:
super: fix emergency thaw deadlock on frozen block devices
do_thaw_all_callback() calls bdev_thaw() while holding sb->s_umount
exclusively. If the block device was frozen via bdev_freeze() dropping
the last block layer freeze reference calls fs_bdev_thaw() which
reacquires s_umount:
do_thaw_all_callback(sb)
super_lock_excl(sb) # holds sb->s_umount
bdev_thaw(sb->s_bdev)
mutex_lock(&bdev->bd_fsfreeze_mutex)
# bd_fsfreeze_count drops 1 -> 0
bd_holder_ops->thaw == fs_bdev_thaw
get_bdev_super(bdev)
bdev_super_lock(bdev, true)
super_lock(sb, true)
down_write(&sb->s_umount) # same task: deadlock
The emergency thaw worker deadlocks against itself holding both
s_umount and bd_fsfreeze_mutex. That fscks any subsequent unmount,
freeze, or thaw of that filesystem and block device.
[ 81.878470] sysrq: Show Blocked State
[ 81.880140] task:kworker/0:1 state:D stack:0 pid:11 tgid:11 ppid:2 task_flags:0x4208060 flags:0x00080000
[ 81.884876] Workqueue: events do_thaw_all
[ 81.886656] Call Trace:
[ 81.887759] <TASK>
[ 81.888763] __schedule+0x579/0x1420
[ 81.890372] schedule+0x3a/0x100
[ 81.891794] schedule_preempt_disabled+0x15/0x30
[ 81.893848] rwsem_down_write_slowpath+0x1ea/0x900
[ 81.895191] ? __pfx_do_thaw_all_callback+0x10/0x10
[ 81.896528] down_write+0xbd/0xc0
[ 81.897505] super_lock+0x91/0x180
[ 81.898457] ? __mutex_lock+0xa99/0x1140
[ 81.900748] ? __mutex_unlock_slowpath+0x1f/0x400
[ 81.902069] bdev_super_lock+0x5b/0x150
[ 81.903132] get_bdev_super+0x10/0x60
[ 81.904042] fs_bdev_thaw+0x23/0xf0
[ 81.904755] bdev_thaw+0x82/0x100
[ 81.905484] do_thaw_all_callback+0x2c/0x50
[ 81.906298] __iterate_supers+0x5d/0x130
[ 81.907067] do_thaw_all+0x20/0x40
[ 81.907739] process_one_work+0x206/0x5e0
[ 81.908545] worker_thread+0x1e2/0x3c0
[ 81.909339] ? __pfx_worker_thread+0x10/0x10
[ 81.910171] kthread+0xf4/0x130
[ 81.910799] ? __pfx_kthread+0x10/0x10
[ 81.911528] ret_from_fork+0x2e2/0x3b0
[ 81.912259] ? __pfx_kthread+0x10/0x10
[ 81.913010] ret_from_fork_asm+0x1a/0x30
[ 81.913806] </TASK>
bdev_super_lock() even documents the violated requirement with
lockdep_assert_not_held(&sb->s_umount).
Acquiring bd_fsfreeze_mutex under s_umount also inverts the
bd_fsfreeze_mutex vs. s_umount ordering established by
bdev_{freeze,thaw}() and can thus ABBA against a concurrent block-layer
freeze even when the recursive path isn't hit.
Fix this by not holding s_umount around the bdev_thaw() loop at all. Pin
the superblock with an active reference instead as
filesystems_freeze_callback() does. The active reference keeps the
superblock from being shut down and so ->s_bdev stays valid without
holding s_umount. The block-layer-held freeze is dropped by
fs_bdev_thaw() with FREEZE_MAY_NEST | FREEZE_HOLDER_USERSPACE exactly as
a regular unfreeze would and thaw_super_locked() handles
filesystem-level freezes as before.
The emergency thaw path has deadlocked like this in one form or
another for a long long time but the current exclusively-held
shape dates back to commit [1] where thaw_bdev() already ended in
thaw_super() with s_umount held by do_thaw_all_callback(). |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: defer destroy_previous_session() until after NTLM authentication
In ntlm_authenticate(), destroy_previous_session() is called using a
user pointer resolved from the client-supplied NTLM blob username field
before the NTLMv2 response is validated. An authenticated attacker can
set the NTLM blob username to match a victim account and set
PreviousSessionId to the victim's session ID; destroy_previous_session()
destroys the victim's session while ksmbd_decode_ntlmssp_auth_blob()
subsequently rejects the request with -EPERM.
Move destroy_previous_session() and the prev_id assignment to after
ksmbd_decode_ntlmssp_auth_blob() returns success and use sess->user
rather than the pre-authentication lookup result. This matches the
ordering already used by krb5_authenticate(), where
destroy_previous_session() is called only after
ksmbd_krb5_authenticate() returns success. |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: validate num_subauth when copying ACE in set_ntacl_dacl
set_ntacl_dacl() copies each ACE from the attacker-controlled stored
security descriptor verbatim into the response DACL without checking
sid.num_subauth. The ACE bytes (including an unchecked num_subauth)
originate from an authenticated SMB2_SET_INFO(SecInfo=DACL) that is
stored raw via ksmbd_vfs_set_sd_xattr(); parse_dacl() rejects a bad ACE
with `break` rather than an error, so parse_sec_desc() still returns
success and the malformed SD reaches the xattr intact.
On a subsequent SMB2_QUERY_INFO(SecInfo=DACL) for an inode carrying a
POSIX access ACL, build_sec_desc() -> set_ntacl_dacl() ->
set_posix_acl_entries_dacl() walks the copied ACEs and reads
ntace->sid.sub_auth[ntace->sid.num_subauth - 1]
with num_subauth taken straight from the stored SD. Since sub_auth[]
is fixed at SID_MAX_SUB_AUTHORITIES (15), a crafted num_subauth (e.g.
255) drives an out-of-bounds heap read of ~1 KB with an offset fully
controlled by an authenticated client.
The sibling functions already gate this field:
parse_dacl() -- num_subauth == 0 || > SID_MAX_SUB_AUTHORITIES
parse_sid() -- num_subauth > SID_MAX_SUB_AUTHORITIES
smb_copy_sid() -- min_t(u8, num_subauth, SID_MAX_SUB_AUTHORITIES)
set_ntacl_dacl() is the lone inconsistent path that omits the check.
Add the same num_subauth validation in set_ntacl_dacl() before copying
the ACE, matching the gate already enforced by parse_dacl(). |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: restore DACL size on check_add_overflow() to avoid malformed ACL
check_add_overflow() unconditionally writes the truncated sum into *d
even on overflow, per its contract in include/linux/overflow.h.
The four check_add_overflow() guards in set_posix_acl_entries_dacl()
and set_ntacl_dacl() break out of the ACE-building loops on overflow,
but the truncated *size is then consumed downstream at the end of
set_ntacl_dacl():
pndacl->size = cpu_to_le16(le16_to_cpu(pndacl->size) + size);
This produces an on-wire NT ACL whose pndacl->size under-reports the
bytes actually written by the preceding fill_ace_for_sid()/memcpy()
calls, yielding a malformed ACL that can trigger out-of-bounds reads
when re-parsed by clients or ksmbd itself.
Restore *size to its pre-addition value on each overflow branch (via
`*size -= ace_sz` / `size -= nt_ace_size`) so that after the break,
*size once again holds the cumulative size of the successfully-written
ACEs. The committed ACL is then truncated-but-self-consistent rather
than malformed.
The ksmbd DACL builders are the only check_add_overflow() sites found
where an overflow path breaks out of a loop and the destination value
is consumed afterward. The other nearby break-style cases either
return -EINVAL on overflow (transport_ipc.c) or break without
consuming the overflowed destination value afterward (buildid.c). |
| In the Linux kernel, the following vulnerability has been resolved:
dma-buf/udmabuf: skip redundant cpu sync to fix cacheline EEXIST warning
When CONFIG_DMA_API_DEBUG_SG is enabled, importing a udmabuf into a DRM
driver (e.g. amdgpu for video playback in GNOME Videos / Showtime)
triggers a spurious warning:
DMA-API: amdgpu 0000:03:00.0: cacheline tracking EEXIST, \
overlapping mappings aren't supported
WARNING: kernel/dma/debug.c:619 at add_dma_entry+0x473/0x5f0
The call chain is:
amdgpu_cs_ioctl
-> amdgpu_ttm_backend_bind
-> dma_buf_map_attachment
-> [udmabuf] map_udmabuf -> get_sg_table
-> dma_map_sgtable(dev, sg, direction, 0) // attrs=0
-> debug_dma_map_sg -> add_dma_entry -> EEXIST
This happens because udmabuf builds a per-page scatter-gather list via
sg_set_folio(). When begin_cpu_udmabuf() has already created an sg
table mapped for the misc device, and an importer such as amdgpu maps
the same pages for its own device via map_udmabuf(), the DMA debug
infrastructure sees two active mappings whose physical addresses share
cacheline boundaries and warns about the overlap.
The DMA_ATTR_SKIP_CPU_SYNC flag suppresses this check in
add_dma_entry() because it signals that no CPU cache maintenance is
performed at map/unmap time, making the cacheline overlap harmless.
All other major dma-buf exporters already pass this flag:
- drm_gem_map_dma_buf() passes DMA_ATTR_SKIP_CPU_SYNC
- amdgpu_dma_buf_map() passes DMA_ATTR_SKIP_CPU_SYNC
The CPU sync at map/unmap time is also redundant for udmabuf:
begin_cpu_udmabuf() and end_cpu_udmabuf() already perform explicit
cache synchronization via dma_sync_sgtable_for_cpu/device() when CPU
access is requested through the dma-buf interface.
Pass DMA_ATTR_SKIP_CPU_SYNC to dma_map_sgtable() and
dma_unmap_sgtable() in udmabuf to suppress the spurious warning and
skip the redundant sync. |
| In the Linux kernel, the following vulnerability has been resolved:
can: esd_usb: kill anchored URBs before freeing netdevs
esd_usb_disconnect() frees each CAN netdev with free_candev() inside
its per-netdev loop and only calls unlink_all_urbs(dev) afterwards.
The per-netdev private data (struct esd_usb_net_priv) is embedded in
the net_device allocation returned by alloc_candev(), so once
free_candev() has run, dev->nets[i] points to freed memory.
unlink_all_urbs() then dereferences the freed dev->nets[i] to kill the
per-netdev TX anchor (usb_kill_anchored_urbs(&priv->tx_submitted)),
clear active_tx_jobs, and reset priv->tx_contexts[].
Reorder the teardown so the anchored URBs are killed before the netdevs
are freed, matching other CAN/USB drivers in the same directory such as
ems_usb, usb_8dev and mcba_usb, which unregister, then unlink, then
free: unregister the netdevs first (which stops their TX queues), call
unlink_all_urbs(dev) once, then free the netdevs.
This issue was found by an in-house static analysis tool. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: udc: bdc: free IRQ and drain func_wake_notify before teardown
The Broadcom BDC UDC driver registers its IRQ handler with
devm_request_irq() in bdc_udc_init(), so the IRQ is released by devm
only after bdc_remove() returns. devm releases resources in reverse
LIFO order, but bdc_remove() runs bdc_udc_exit() and bdc_hw_exit() ->
bdc_mem_free() manually before returning: bdc_udc_exit() tears down
individual endpoint objects via bdc_free_ep(), while bdc_hw_exit() ->
bdc_mem_free() frees and NULLs the DMA-coherent status-report ring
(bdc->srr.sr_bds) and kfree()s bdc->bdc_ep_array. Both happen while
the IRQ handler (bdc_udc_interrupt, requested with IRQF_SHARED)
remains deliverable in the window up to the post-remove devm
free_irq().
On receipt of a shared interrupt in that window, bdc_udc_interrupt()
dereferences bdc->srr.sr_bds[bdc->srr.dqp_index] (NULL or freed DMA)
and dispatches sr_handler callbacks that index into bdc_ep_array,
causing a NULL-deref or use-after-free.
The same window affects the delayed_work bdc->func_wake_notify, which is
armed from the IRQ handler via bdc_sr_uspc() -> handle_link_state_change()
-> schedule_delayed_work() and may self-rearm from its own callback
bdc_func_wake_timer(). No cancel exists anywhere in the driver, so a
queued work item that fires after bdc_remove() returns and the bdc
structure is devm-freed dereferences freed memory.
Replace devm_request_irq() with request_irq() and add an explicit
free_irq(bdc->irq, bdc) in bdc_remove(). Clear BDC_GIE before
free_irq() to stop the device from asserting interrupts, then
free_irq() drains any in-flight handler, then cancel_delayed_work_sync()
drains the func_wake_notify delayed work. This ordering ensures the
IRQ handler and delayed work cannot interfere with the subsequent
endpoint and DMA teardown in bdc_udc_exit() and bdc_hw_exit(). Wire the
matching free_irq() into the bdc_udc_init() error path so the IRQ is
released on probe failure, and route the bdc_init_ep() failure through
err0 instead of returning directly.
This issue was found by an in-house static analysis tool. |
| In the Linux kernel, the following vulnerability has been resolved:
mm: do file ownership checks with the proper mount idmap
Ever since idmapped mounts were introduced, inode ownership checks (for
side-channel protection) in mincore() and madvise(MADV_PAGEOUT) were done
against the nop_mnt_idmap, which completely ignores the file's mount's
idmap. This results in odd edgecases like:
1) mount/bind-mount with an idmap userA:userB:1
2) userB runs an owner_or_capable() check on file that is owned by userA
on-disk/in-memory, but owned by userB after idmap translation
3) owner_or_capable() mysteriously fails as the correct idmap wasn't supplied
In the case of mincore/madvise MADV_PAGEOUT, this is usually benign,
because file_permission(file, MAY_WRITE) will probably succeed, as it uses
the proper idmap internally, but it does not need to be the case on e.g a
0444 file where even the owner itself doesn't have permissions to write to
it.
Since this is clearly not trivial to get right, introduce a
file_owner_or_capable() that can carry the correct semantics, and switch
the various users in mm to it.
The issue was found by manual code inspection & an off-list discussion
with Jan Kara. |
| In the Linux kernel, the following vulnerability has been resolved:
fpga: dfl-afu: validate DMA mapping length in afu_dma_map_region()
afu_ioctl_dma_map() accepts a 64-bit length from userspace via
DFL_FPGA_PORT_DMA_MAP ioctl without an upper bound check. The value
is passed to afu_dma_pin_pages() where npages is derived as
length >> PAGE_SHIFT and passed to pin_user_pages_fast() which takes
int nr_pages, causing implicit truncation if length is very large.
Validate map.length at the ioctl entry point before calling
afu_dma_map_region(), rejecting values whose page count exceeds
INT_MAX. |
| In the Linux kernel, the following vulnerability has been resolved:
Input: mms114 - fix touch indexing for MMS134S and MMS136
The MMS134S and MMS136 touch controllers have an event size of 6 bytes
rather than 8 bytes. When __mms114_read_reg() reads the touch data
packet from the device into the touch buffer, the events are packed
tightly at 6-byte intervals. However, the driver iterates through the
events using standard C array indexing (touch[index]), where each
element is sizeof(struct mms114_touch) (8 bytes) apart. As a result, any
touch events beyond the first one are read from incorrect offsets and
parsed improperly.
Fix this by explicitly calculating the byte offset for each touch event
based on the device's specific event size. |
| In the Linux kernel, the following vulnerability has been resolved:
Input: mms114 - reject an oversized device packet size
mms114_interrupt() reads a packet of touch data from the device into a
fixed-size on-stack buffer
struct mms114_touch touch[MMS114_MAX_TOUCH];
which holds MMS114_MAX_TOUCH (10) events of MMS114_EVENT_SIZE (8) bytes,
i.e. 80 bytes. The length of the I2C read into it is taken verbatim from
the device:
packet_size = mms114_read_reg(data, MMS114_PACKET_SIZE);
if (packet_size <= 0)
goto out;
...
error = __mms114_read_reg(data, MMS114_INFORMATION, packet_size,
(u8 *)touch);
packet_size is a single device register byte (0x0F) and the only check
is the lower bound packet_size <= 0; it is never bounded against the
size of touch[]. A malfunctioning, malicious or counterfeit controller
(or an attacker tampering with the I2C bus) can report a packet_size of
up to 255, so __mms114_read_reg() writes up to 175 bytes past the end of
touch[] on the IRQ-thread stack: a stack out-of-bounds write that can
overwrite the stack canary, saved registers and the return address.
A well-formed device never reports more than the buffer holds, so reject
an oversized packet and drop the report, consistent with the handler's
other error paths, rather than reading past the buffer. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/rtrs-srv: Bound RDMA-Write length to chunk size in rdma_write_sg
When the server answers an RTRS READ, rdma_write_sg() builds the source
scatter/gather entry for the IB_WR_RDMA_WRITE that returns data to the
peer. Its length is taken directly from the wire descriptor:
plist->length = le32_to_cpu(id->rd_msg->desc[0].len);
rd_msg points into the chunk buffer that the remote peer filled via
RDMA-WRITE-WITH-IMM (rtrs_srv_rdma_done() -> process_io_req() ->
process_read()), so desc[0].len is attacker-controlled and, before this
change, was only rejected when zero. The source address is the fixed
chunk start (dma_addr[msg_id]) and the source lkey is the PD-wide
local_dma_lkey, which is not tied to the chunk's MR mapping, so the verbs
layer does not constrain the transfer length to max_chunk_size. msg_id
and off are bounded against queue_depth and max_chunk_size in
rtrs_srv_rdma_done(), but desc[0].len is a separate field that was not
checked against the chunk size.
A peer that advertises desc[0].len larger than max_chunk_size can make
the posted RDMA write read past the chunk's mapped region. The resulting
behaviour depends on the IOMMU configuration: with no IOMMU or in
passthrough mode the read may extend into memory adjacent to the chunk
and be returned to the peer, which can disclose host memory; with a
translating IOMMU the out-of-range access is expected to fault and abort
the connection. In either case the transfer exceeds what the protocol
permits and is driven by a remote peer.
Reject a descriptor length above max_chunk_size, mirroring the existing
off >= max_chunk_size bound in rtrs_srv_rdma_done(). Legitimate clients
do not exceed it: the client sets desc[0].len to its MR length, which is
capped at the negotiated max_io_size (max_chunk_size - MAX_HDR_SIZE). |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Reject BPF_MAP_TYPE_INODE_STORAGE creation if BPF LSM is uninitialized
When CONFIG_BPF_LSM=y is set, BPF inode storage maps
(BPF_MAP_TYPE_INODE_STORAGE) are compiled into the kernel. However,
if the BPF LSM is not explicitly enabled at boot time (e.g. omitted
from the "lsm=" boot parameter), lsm_prepare() is never executed for
the BPF LSM.
Consequently, the BPF inode security blob offset
(bpf_lsm_blob_sizes.lbs_inode) is never initialized and remains at
its default compiled size of 8 bytes instead of being updated to a
valid offset past the reserved struct rcu_head (typically 16 bytes
or more).
When a privileged user creates and updates a BPF_MAP_TYPE_INODE_STORAGE
map, bpf_inode() evaluates inode->i_security + 8. This erroneously
aliases the struct rcu_head.func callback pointer at the beginning
of the inode->i_security blob. During subsequent map element cleanup
or inode destruction, writing NULL to owner_storage clears the queued
RCU callback pointer. When rcu_do_batch() later executes the queued
callback, it attempts an instruction fetch at address 0x0, triggering
an immediate kernel panic.
Fix this by introducing a global bpf_lsm_initialized boolean flag
marked with __ro_after_init. Set this flag to true inside bpf_lsm_init()
when the LSM framework successfully registers the BPF LSM. Gate map
allocation in inode_storage_map_alloc() on this flag, returning
-EOPNOTSUPP if the BPF LSM is in turn uninitialized.
This fail-fast approach prevents userspace from allocating inode
storage maps when the supporting BPF LSM infrastructure is absent,
avoiding zombie map states. |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix SID memory leak in set_posix_acl_entries_dacl() on overflow
Commit 299f962c0b02 ("ksmbd: use check_add_overflow() to prevent u16
DACL size overflow") added check_add_overflow() guards that break out
of the ACE-building loops in set_posix_acl_entries_dacl() when the
accumulated DACL size would wrap past 65535.
However, each iteration allocates a struct smb_sid via kmalloc_obj()
at the top of the loop and relies on the kfree(sid) call at the end
of the loop body (the 'pass_same_sid' label in the first loop, and
the explicit kfree at the tail of the second loop) to release it.
The newly introduced 'break' statements bypass those kfree() calls,
leaking the sid buffer every time an overflow is detected.
A malicious or malformed file with enough POSIX ACL entries to trip
the overflow check will leak one or more struct smb_sid allocations
on every request that touches the file's DACL, providing a trivial
kernel memory exhaustion vector.
Free sid before breaking out of the loops to plug the leak. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix linked reg delta tracking when src_reg == dst_reg
Consider the case of rX += rX where src_reg and dst_reg are pointers to
the same bpf_reg_state in adjust_reg_min_max_vals(). The latter first
modifies the dst_reg in-place, and later in the delta tracking, the
subsequent is_reg_const(src_reg)/reg_const_value(src_reg) reads the
post-{add,sub} value instead of the original source.
This is problematic since it sets an incorrect delta, which sync_linked_regs()
then propagates to linked registers, thus creating a verifier-vs-runtime
mismatch. Fix it by just skipping this corner case. |
