| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: use d_instantiate_new() in ntfs_create_inode() and murder syzbot's "WARNING in do_new_mount" saga
ntfs_create_inode() creates a new inode via ntfs_new_inode(). It hashes
it with insert_inode_locked() and so it's marked as I_NEW until
unlock_new_inode().
ntfs 3 calls d_instantiate() in between though... Since the dentry was
already hashed by the lookup before the create any path walk finds it
without touching the parent's i_rwsem and so can lock the inode.
If the inode is a directory unlock_new_inode() calls
lockdep_annotate_inode_mutex_key() and marks i_rwsem with the
i_mutex_dir_key class.
That resets the count and the owner of a lock somebody else may already
hold by now...
syzbot has been spamming us with the same godforsaken bug
"WARNING in do_new_mount"
since 2023. I can't take it anymore so I went looking. Afaict, syzbot's
executor chdirs into a freshly mounted ntfs3 image, creates a
directory and then mounts some pseudofs on it. Everytime the mkdir()
takes longer than syzbot waits mount() runs concurrently:
mkdir("./sys") mount(NULL, "./sys", "sysfs")
ntfs_create_inode()
d_instantiate()
user_path_at() finds the dentry
do_lock_mount()
inode_lock(inode)
namespace_lock()
unlock_new_inode()
lockdep_annotate_inode_mutex_key()
init_rwsem(&inode->i_rwsem)
unlock_mount()
inode_unlock(inode)
The mount side then releases a lock that according to the rwsem nobody
holds:
DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && ...):
count = 0x0, magic = 0xffff888043a854e8, owner = 0x0,
curr 0xffff888000244880, list empty
WARNING: CPU: 0 PID: 5346 at kernel/locking/rwsem.c:1368 __up_write
Call Trace:
inode_unlock include/linux/fs.h:877 [inline]
unlock_mount fs/namespace.c:2892 [inline]
do_new_mount_fc fs/namespace.c:3828 [inline]
do_new_mount+0x777/0xa40 fs/namespace.c:3887
On PREEMPT_RT the same thing shows up as
DEBUG_LOCKS_WARN_ON(rt_mutex_owner(lock) != current)
WARNING: kernel/locking/rtmutex_common.h:193 at rt_mutex_slowunlock
The up_write() underflows the reset count. A following inode_lock() on
that directory then never returns. A path walk into the new directory
racing with the mkdir() corrupts the lock the same way via
inode_lock_shared() in lookup_slow().
Switch to d_instantiate_new() and drop the trailing unlock_new_inode().
All error paths bail out before that point with I_NEW still set and
keep using discard_new_inode().
May we never see this fscking bug report again. |
| In the Linux kernel, the following vulnerability has been resolved:
writeback: bound cleanup_offline_cgwb() rescans by rotating scanned inodes
cleanup_offline_cgwb() prepares at most WB_MAX_INODES_PER_ISW inodes
per call and is called again until the dying wb is drained, but every
call walks wb->b_attached and then wb->b_dirty_time from the same end.
Inodes already prepared (they stay on the list with I_WB_SWITCH set
until the switch worker runs) and inodes that cannot be switched
(I_FREEING, I_WILL_FREE, !SB_ACTIVE, DAX, already on the target wb)
stay where they are, so each pass rescans a growing run of them under
wb->list_lock and a full drain is quadratic in the number of inodes on
the list. With ~17M inodes attached to one dying cgwb we saw this end
in soft lockups, with CPUs reported stuck for 21-48s.
Walk both lists from the oldest end and move every scanned inode to
the newest end, so the next pass starts where the previous one stopped
and the drain becomes linear. b_attached is unordered, so nobody sees
the reorder there. b_dirty_time is ordered by dirtied_when, but the
oldest unscanned inode stays at the end move_expired_inodes() picks
from, sync takes the whole list regardless of order, and prepared
inodes leave the list as soon as the switch work runs and get a new
dirtied_time_when on the new wb anyway, so the only inodes left out of
order are the ones that can never switch (DAX), and only on the dying
wb. |
| In the Linux kernel, the following vulnerability has been resolved:
workqueue: Fix NULL current_pwq deref in flush dependency check
check_flush_dependency() uses current_wq_worker() to determine whether
the caller is a workqueue worker and then dereferences worker->current_pwq
to test whether the current workqueue is WQ_MEM_RECLAIM.
current_wq_worker() only means that %current has PF_WQ_WORKER set. A
kworker can reach check_flush_dependency() while it is not executing a
work item. One such path is worker_thread() acting as the pool manager,
where create_worker() does GFP_KERNEL allocation and the allocation path
invokes the OOM notifier. In that state worker->current_pwq is NULL
because current_pwq is set only by process_one_work() and cleared again
after the work function returns.
[ 416.760634][ T375] Call trace:
[ 416.760638][ T375] check_flush_dependency+0x80/0x120 (P)
[ 416.760648][ T375] __flush_work+0x98/0x224
[ 416.760657][ T375] flush_work+0x30/0x44
[ 416.760665][ T375] ...
[ 416.760710][ T375] blocking_notifier_call_chain+0x58/0xa0
[ 416.760719][ T375] out_of_memory+0xb4/0x458
[ 416.760730][ T375] __alloc_pages_may_oom+0x11c/0x1a8
[ 416.760739][ T375] __alloc_pages_slowpath+0x314/0x46c
[ 416.760746][ T375] __alloc_frozen_pages_noprof+0x110/0x1a4
[ 416.760753][ T375] new_slab+0x12c/0x484
[ 416.760759][ T375] ___slab_alloc+0x7a8/0xc7c
[ 416.760765][ T375] __slab_alloc+0x74/0xd8
[ 416.760772][ T375] __kmalloc_cache_node_noprof+0x2ac/0x304
[ 416.760779][ T375] alloc_worker+0x28/0x60
[ 416.760785][ T375] create_worker+0x4c/0x20c
[ 416.760790][ T375] worker_thread+0xe8/0x2b8
[ 416.760796][ T375] kthread+0x1a8/0x200
[ 416.760805][ T375] ret_from_fork+0x10/0x20
Guard the WQ_MEM_RECLAIM-worker warning with worker->current_pwq. If the
kworker is not currently executing a work item, there is no current
workqueue to diagnose with that warning. The PF_MEMALLOC warning is left
unchanged so explicit reclaim context flushing a !WQ_MEM_RECLAIM target
is still reported. |
| In the Linux kernel, the following vulnerability has been resolved:
writeback: report a Tasks-RCU quiescent state per cgwb drain pass
cleanup_offline_cgwbs_workfn() drains a dying cgwb by calling
cleanup_offline_cgwb() until it returns false, with a cond_resched()
between passes. On a CONFIG_PREEMPTION kernel that cond_resched() does
nothing: _cond_resched() is a plain "return 0", and under PREEMPT_DYNAMIC
the full and lazy modes disable it. Since commit 7dadeaa6e851 ("sched:
Further restrict the preemption modes") those are the only two models on
the architectures with PREEMPT_LAZY support, arm64 and x86 among them, so
the drain loop never reports a Tasks-RCU quiescent state.
A worker draining a cgwb with millions of attached inodes runs for
minutes. On a 6.18 arm64 host in lazy mode the cgwb worker drained one
dying cgroup's writeback domain for over 11 minutes. A BPF program unlink
(bpf_trampoline_unlink_prog -> bpf_trampoline_update ->
unregister_ftrace_direct -> ftrace_shutdown -> synchronize_rcu_tasks())
waited on that grace period while holding the trampoline mutex, 42 tasks
queued behind it in D state, and the hung task detector fired at 614 s and
panicked the host. Any BPF or ftrace detach during a long drain inherits
the drain's length.
Fix this by calling cond_resched_tasks_rcu_qs() so we do not stall out
anybody who calls sycnrhonize_rcu_tasks(). We put this in a do { } while
loop because if we have many small cgroups cleanup_offline_cgwb() will
return false and we will never call cond_resched_tasks_rcu_qs(), creating
the same problem. |
| In the Linux kernel, the following vulnerability has been resolved:
fsl/fman: Fix clk reference leak in read_dts_node()
of_clk_get() returns a clock with its reference count incremented, but
read_dts_node() only uses it to read the rate and never calls clk_put().
The clock is not stored anywhere, so the reference cannot be released
later either.
Release the clock once its rate has been read, which also covers the
error path taken when the rate is zero. |
| In the Linux kernel, the following vulnerability has been resolved:
ipe: fix use-after-free when auditing a newly loaded policy
new_policy() audits the policy after ipe_new_policyfs_node() publishes it
and drops the new directory's inode lock. A concurrent delete can free
the policy while ipe_audit_policy_load() is still using it.
Audit the successful load under that lock.
[FW: remove model name according to latest guideline] |
| In the Linux kernel, the following vulnerability has been resolved:
ipe: protect the dm-verity root hash with RCU
ipe_bdev_setintegrity() frees the old root hash when dm-verity publishes
a new one on ->preresume, while policy evaluation can still be
dereferencing it.
Protect the root hash with RCU. The evaluation path already runs under
rcu_read_lock().
[FW: remove model name according to latest guideline] |
| In the Linux kernel, the following vulnerability has been resolved:
ipv6: do not let ipv6_find_hdr() return an offset past the packet end
ipv6_find_hdr() walks the extension header chain, skipping each header by
the length that header itself declares. ipv6_optlen() returns up to 2048,
and the skip is never checked against skb->len, so the offset stored in
*offset can point past the end of the packet.
openvswitch installs that offset as the transport header, and
update_ipv6_checksum() then reads and writes the transport checksum field
out of bounds:
BUG: KASAN: slab-use-after-free in inet_proto_csum_replace16+0x445/0x470
Read of size 2 at addr ffff88810b754b06 by task ovs_ipv6_oob/629
CPU: 4 UID: 1000 PID: 629 Comm: ovs_ipv6_oob Tainted: G N 7.3.0-rc3+ #348
Call Trace:
inet_proto_csum_replace16+0x445/0x470
set_ipv6_addr+0x3dd/0x460
do_execute_actions+0x6a3d/0x7c40
ovs_execute_actions+0xfd/0x480
ovs_packet_cmd_execute+0xc38/0xf20
genl_rcv_msg+0x59e/0x870
netlink_rcv_skb+0x18b/0x450
genl_rcv+0x2d/0x40
netlink_unicast+0x6bc/0xa20
The buggy address belongs to the object at ffff88810b754980
which belongs to the cache skbuff_small_head of size 704
The buggy address is located 390 bytes inside of
freed 704-byte region [ffff88810b754980, ffff88810b754c40)
Other callers use that offset too, so bound it here rather than in one
caller.
Reject a header whose declared length does not fit in the packet.
ipv6_find_hdr() already fails with -EBADMSG on a malformed chain, so this
adds no new failure mode. |
| In the Linux kernel, the following vulnerability has been resolved:
ipv6: sr: enforce exact attribute length for SEG6_ATTR_DST
In seg6_genl_policy, SEG6_ATTR_DST is defined with .type = NLA_BINARY and
.len = sizeof(struct in6_addr). For NLA_BINARY, .len only enforces the
maximum payload length and permits shorter payloads (e.g., 0 bytes).
When seg6_genl_set_tunsrc() copies sizeof(struct in6_addr) bytes via
kmemdup(val, sizeof(*val), GFP_KERNEL), a short SEG6_ATTR_DST attribute
triggers a 16-byte out-of-bounds read past skb->tail into uninitialized
skb->head memory, which is stored in sdata->tun_src and leaked back to
userspace via SEG6_CMD_GET_TUNSRC.
Switch SEG6_ATTR_DST in seg6_genl_policy to
NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)) so that generic netlink
validation rejects any attribute whose length is not exactly
sizeof(struct in6_addr) with -ERANGE.
Tested in QEMU against Linux 7.3.0-rc3 by sending a SEG6_CMD_SET_TUNSRC
Generic Netlink message with a 0-byte SEG6_ATTR_DST attribute followed
by SEG6_CMD_GET_TUNSRC. On the unfixed kernel, SEG6_CMD_SET_TUNSRC
succeeds (err = 0) and SEG6_CMD_GET_TUNSRC leaks 16 bytes of
uninitialized kernel heap memory (tun_src =
836a61ecc4d25a1042a8d60411cfb378); with this patch applied,
SEG6_CMD_SET_TUNSRC is rejected by netlink policy validation with
-ERANGE (-34) and tun_src remains zeroed. |
| In the Linux kernel, the following vulnerability has been resolved:
kprobes: Fix permanent hang when flushing the kprobe optimizer
Writing 0 to /proc/sys/debug/kprobes-optimization while a kprobe is
jump-optimized never returns. The writer sleeps in D state forever with
kprobe_sysctl_mutex held, so any later read or write of that sysctl
hangs as well. For example, with vfs_read+9 as an optimizable address
in this build:
# cd /sys/kernel/tracing
# echo 'p:myprobe vfs_read+9' >> kprobe_events
# echo 1 > events/kprobes/myprobe/enable
# # wait until /sys/kernel/debug/kprobes/list shows [OPTIMIZED]
# echo 0 > /proc/sys/debug/kprobes-optimization
INFO: task sh:246 blocked for more than 10 seconds.
Call Trace:
<TASK>
__schedule+0x1176/0x4f70
schedule+0xdc/0x2c0
schedule_timeout+0x17b/0x260
wait_for_completion+0x173/0x3c0
wait_for_kprobe_optimizer_locked+0xbc/0x130
proc_kprobes_optimization_handler+0x156/0x1b0
proc_sys_call_handler+0x324/0x490
vfs_write+0x52d/0xfe0
ksys_write+0xff/0x200
do_syscall_64+0x106/0x630
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
...
INFO: task cat:265 is blocked on a mutex likely owned by task sh:246.
wait_for_kprobe_optimizer_locked() reinitializes optimizer_completion,
asks the optimizer thread to flush and sleeps in wait_for_completion().
The thread drains the (un)optimizing lists, but calls complete() only
if completion_done() is true, i.e. if the completion is already done,
which never happens while someone waits. disarm_all_kprobes() and
kprobe_trace_self_tests_init() wait the same way.
Calling complete() unconditionally would not be enough: the waiter
drops kprobe_mutex while it sleeps, and nothing else serializes the
sysctl handler against the debugfs "enabled" file. A second flusher
that still finds the lists non-empty, e.g. because a disabled probe is
queued for unoptimizing, reinitializes the completion under the first:
sysctl write debugfs "enabled" write
unoptimize_all_kprobes()
wait_for_kprobe_optimizer_locked()
init_completion(c)
mutex_unlock(&kprobe_mutex)
wait_for_completion(c)
disarm_all_kprobes()
wait_for_kprobe_optimizer_locked()
init_completion(c)
// c->wait is reset, the first
// waiter is off the queue
mutex_unlock(&kprobe_mutex)
wait_for_completion(c)
kprobe_optimizer()
complete(c)
// wakes the debugfs writer only
where c is &optimizer_completion. Lining up the two writes during an
optimizer pass loses the sysctl writer this way.
Replace the completion with a counter of optimizer passes, bumped at the
end of each pass and signalled with wake_up_var_locked(), both under
kprobe_mutex. A flusher samples the count and waits with
wait_var_event_mutex(), which drops kprobe_mutex only while sleeping, so
a new count means a whole pass ran in the meantime. Nothing is
reinitialized, so several flushers can sleep in the wait at once. |
| In the Linux kernel, the following vulnerability has been resolved:
gpio: arizona: Fix runtime PM leak in arizona_gpio_direction_out()
Switching a persistent GPIO line from input to output acquires a
runtime PM reference on the parent device, but if the subsequent
regmap_update_bits() fails the reference is never dropped and no later
direction_in() can balance it since the direction was never changed.
Drop the reference on the update failure path. |
| In the Linux kernel, the following vulnerability has been resolved:
gpio: cdev: fix kernel stack leak to user-space in error path
If we fail to acquire the GPIO chip guard in gpio_desc_to_lineinfo(), we
return immediately before zeroing the info struct we'll end up passing
to the user-space later in lineinfo_get_v1(). This may leak the kernel
stack contents. Make gpio_desc_to_lineinfo() return int so that the
-ENODEV returned on failure to acquire the guard can be propagated to
the callers.
While not strictly necessary: move the memset() before trying to acquire
the SRCU read lock too for good measure. |
| In the Linux kernel, the following vulnerability has been resolved:
gpio: zynq: fix runtime PM leak on request error path
pm_runtime_get_sync() leaves the usage counter incremented even when it
fails, and zynq_gpio_request() returns the error without dropping it.
gpiolib does not call ->free() when ->request() fails, so zynq_gpio_free(),
which holds the only matching pm_runtime_put(), never runs. The reference
is leaked and the controller can no longer runtime-suspend, so its clock
stays enabled.
Switch to pm_runtime_resume_and_get(), which only increments the usage
counter on success. |
| In the Linux kernel, the following vulnerability has been resolved:
llc: reserve device headroom for allocated frames
llc_alloc_frame() reserves link-layer headroom using the device type.
This is insufficient for stacked Ethernet devices such as VLAN devices,
where vlan_dev_hard_header() pushes a VLAN header before the lower
device's Ethernet header. An LLC response on such a device can
therefore underflow skb headroom in eth_header().
Use LL_RESERVED_SPACE() to account for the device's actual required
headroom while preserving the existing LLC device-type check. |
| In the Linux kernel, the following vulnerability has been resolved:
mctp: route: iterate socket tag list in mctp_lookup_prealloc_tag()
When a socket transmits a packet with MCTP_TAG_PREALLOC set,
mctp_lookup_prealloc_tag() iterates over the per-netns &mns->keys list
and matches netid, req_tag, peer_addr, and manual_alloc, without
checking whether tmp->sk == &msk->sk. This allows any MCTP socket in the
same network namespace to use and consume another socket's preallocated
tag.
Iterate the socket's own tag list (&msk->keys via sklist) instead of the
namespace-wide &mns->keys list in mctp_lookup_prealloc_tag(), ensuring
that only tags allocated by msk are matched.
Tested in QEMU against Linux 7.3.0-rc3 by allocating a manual tag
(0x18) on socket A via SIOCMCTPALLOCTAG for peer EID 9 and sending a
4-byte message with MCTP_TAG_PREALLOC from socket B in the same network
namespace. On the unfixed kernel, sendto(sock_b) using socket A's
preallocated tag succeeds (ret = 4); with this patch applied,
sendto(sock_b) fails with -ENOENT (errno = 2) while sendto(sock_a)
succeeds (ret = 4). |
| In the Linux kernel, the following vulnerability has been resolved:
rds: ib: Clear the sg list when mapping an MR fails
rds_ib_map_frmr() stores the caller's scatterlist in the MR before DMA
mapping and registration can fail. On failure, __rds_rdma_map() unpins
the pages and frees the scatterlist, but rds_ib_free_frmr() can still
return the MR to the pool with the stale pointer set.
This leaves the pool with a dangling scatterlist and can lead to local
privilege escalation. KASAN detects the resulting use-after-free when the
MR is later torn down:
BUG: KASAN: slab-use-after-free in __rds_ib_teardown_mr
Read of size 8
Call Trace:
__rds_ib_teardown_mr
rds_ib_unreg_frmr
rds_ib_flush_mr_pool
rds_ib_flush_mrs
rds_free_mr
rds_setsockopt
Store the scatterlist in the MR only after DMA mapping succeeds. If DMA
mapping fails, return directly while the MR fields remain clear; the caller
keeps ownership of the scatterlist and its pinned pages. If a later
registration step fails, unmap the scatterlist and clear the MR fields
before returning. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/client: fix restore of partially initialized client
I got a null-ptr-deref report when closing a DRM file descriptor:
WARNING: drivers/gpu/drm/drm_atomic.c:2031 at
__drm_atomic_helper_set_config+0x18e/0x1b0 [drm]
Call Trace:
drm_client_modeset_commit_atomic+0x16b/0x220 [drm]
drm_client_modeset_commit_locked+0x56/0x160 [drm]
drm_client_modeset_commit+0x21/0x40 [drm]
__drm_fb_helper_restore_fbdev_mode_unlocked.part.0+0x7b/0x80
drm_fbdev_client_restore+0xe/0x20 [drm_client_lib]
drm_client_dev_restore+0x9f/0xc0 [drm]
drm_release+0xc5/0xe0 [drm]
The warning is followed by a NULL pointer dereference:
BUG: kernel NULL pointer dereference, address: 0000000000000008
RIP:
__drm_fb_helper_restore_fbdev_mode_unlocked.part.0+0x41/0x80
[drm_kms_helper]
Call Trace:
drm_fbdev_client_restore+0xe/0x20 [drm_client_lib]
drm_client_dev_restore+0x9f/0xc0 [drm]
drm_release+0xc5/0xe0 [drm]
__fput+0xdc/0x2b0
__x64_sys_close+0x39/0x80
do_syscall_64+0x8d/0x460
entry_SYSCALL_64_after_hwframe+0x76/0x7e
drm_client_register() adds the DRM client to the device client list
before invoking the initial hotplug callback. If the hotplug callback
fails, the client remains registered.
For the fbdev client, a failure during drm_fb_helper_initial_config()
causes the partially initialized fbdev helper to be cleaned up.
drm_fb_helper_fini() releases fb_helper->info and leaves it NULL.
The fbdev client therefore remains registered even though there is no
fully initialized framebuffer device.
Later, when userspace closes the DRM file descriptor, drm_release()
can invoke the restore callbacks of registered DRM clients:
drm_release()
drm_client_dev_restore()
drm_fbdev_client_restore()
drm_fb_helper_restore_fbdev_mode_unlocked()
drm_fbdev_client_restore() currently restores the fbdev state
unconditionally. For a partially initialized fbdev client this can
submit an incomplete modeset state and subsequently access fbdev
state which has not been initialized, resulting in the warning and
NULL pointer dereference above.
drm_fbdev_client_unregister() already uses fb_helper->info to
distinguish a fully probed framebuffer device from a partially
initialized client.
Use the same condition in drm_fbdev_client_restore() and skip restore
if no framebuffer device has been successfully initialized. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/imagination: Propagate map failures correctly from pvr_mmu_map_sgl()
Map failure from pvr_mmu_map_sgl() interface was not returned correctly
to pvr_mmu_map() interface. This resulted in pvr_mmu_map() interface to
continue instead of returning an error to caller.
Fix it by returning a proper error code from pvr_mmu_map_sgl() interface.
Call stack for crash:
[ 1179.286237] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008
[ 1179.295067] Mem abort info:
[ 1179.297877] ESR = 0x0000000096000004
[ 1179.301656] EC = 0x25: DABT (current EL), IL = 32 bits
[ 1179.306987] SET = 0, FnV = 0
[ 1179.310048] EA = 0, S1PTW = 0
[ 1179.313198] FSC = 0x04: level 0 translation fault
[ 1179.318096] Data abort info:
[ 1179.320993] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[ 1179.326483] CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[ 1179.331546] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[ 1179.336895] user pgtable: 4k pages, 48-bit VAs, pgdp=000000009822a000
[ 1179.343402] [0000000000000008] pgd=0000000000000000, p4d=0000000000000000
[ 1179.350243] Internal error: Oops: 0000000096000004 [#2] SMP
[ 1179.355908] Modules linked in: powervr gpu_sched drm_shmem_helper drm_gpuvm drm_exec xhci_plat_hcd xhci_hcd dwc3 usbcore usb_common snd_soc_simple_card snd_soc_simple_card_utils dwc3_am62 at24 sa2ul sha512 libsha512 sha256 authenc sch_fq_codel fuse dm_mod ipv6
[ 1179.378992] CPU: 1 UID: 1000 PID: 680 Comm: deqp-vk Tainted: G D 6.17.0 #1 PREEMPT
[ 1179.388120] Tainted: [D]=DIE
[ 1179.390994] Hardware name: Texas Instruments AM625 SK (DT)
[ 1179.396467] pstate: 00000005 (nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 1179.403415] pc : pvr_mmu_op_context_unmap_curr_page+0x6c/0x134 [powervr]
[ 1179.410140] lr : pvr_mmu_op_context_unmap_curr_page+0x58/0x134 [powervr]
[ 1179.416848] sp : ffff8000839ab8c0
[ 1179.420153] x29: ffff8000839ab8c0 x28: 0000000000000001 x27: 000000008f386000
[ 1179.427283] x26: ffff000016d1df98 x25: 0000000000247000 x24: 00000000000001e6
[ 1179.434413] x23: 0000000000000002 x22: 000000000000ffff x21: 0000000000000247
[ 1179.441540] x20: 0000000000000245 x19: ffff000016d1df60 x18: 0000000000000002
[ 1179.448668] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000001
[ 1179.455793] x14: 0000000000060810 x13: ffff80007fffffff x12: ffff000004190480
[ 1179.462921] x11: ffff8000853f7000 x10: ffff8000811ae000 x9 : ffff0000041900b8
[ 1179.470051] x8 : 0000000000000000 x7 : 00000000990c4001 x6 : 0000000000000007
[ 1179.477177] x5 : ffff000016d1df60 x4 : 0000000000000000 x3 : ffff00000a7d8000
[ 1179.484306] x2 : 00000000000001ff x1 : 0000000000000000 x0 : 0000000000000000
[ 1179.491433] Call trace:
[ 1179.493872] pvr_mmu_op_context_unmap_curr_page+0x6c/0x134 [powervr] (P)
[ 1179.500582] pvr_mmu_map+0x31c/0x388 [powervr]
[ 1179.505027] pvr_vm_gpuva_map+0x40/0x88 [powervr]
[ 1179.509732] __drm_gpuvm_sm_map+0x250/0x44c [drm_gpuvm]
[ 1179.514952] drm_gpuvm_sm_map+0x48/0x5c [drm_gpuvm]
[ 1179.519822] pvr_vm_bind_op_exec+0x64/0x70 [powervr]
[ 1179.524785] pvr_vm_map+0x1f8/0x2a8 [powervr]
[ 1179.529142] pvr_ioctl_vm_map+0x12c/0x188 [powervr]
[ 1179.534018] drm_ioctl_kernel+0xb8/0x128
[ 1179.537941] drm_ioctl+0x21c/0x4ec
[ 1179.541337] __arm64_sys_ioctl+0xac/0x108
[ 1179.545344] invoke_syscall+0x44/0x100
[ 1179.549091] el0_svc_common.constprop.0+0x40/0xe0
[ 1179.553790] do_el0_svc+0x1c/0x28
[ 1179.557106] el0_svc+0x34/0xf0
[ 1179.560159] el0t_64_sync_handler+0xd0/0xe4
[ 1179.564334] el0t_64_sync+0x198/0x19c
[ 1179.567996] Code: 54000300 35000360 f9402261 79409a62 (f9400421)
[ 1179.574081] ---[ end trace 0000000000000000 ]--- |
| In the Linux kernel, the following vulnerability has been resolved:
drm/i915: fix incorrect RCU teardown order
i915_gem_busy_ioctl uses dma_resv_for_each_fence_unlocked() to iterate
over the fences in an GEM object without holding a reference but only
the RCU read side lock.
What can happen here is that the GEM object is destroyed concurrently
while i915_gem_busy_ioctl is still running. This won't free the GEM
objects memory, but still drops all the dma_fence references.
Now when dma_resv_for_each_fence_unlocked() sees a destroyed dma_fence it
assumes that a new fence list was installed and re-starts the loop.
But in the case of a destroyed GEM object a new fence list is never
installed, only the old one freed and therefore the iteration never
finishes resulting in an endless loop.
The solution is to drop the fence references only after the RCU grace
period.
The fixes tag is not necessary the patch introducing the problem, but the
one making it so worse that we need to address it.
This problem was pointed out by Sashiko-bot.
(cherry picked from commit 5113479556025093bf8133bb2dcaa33be2d50921) |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdkfd: fix use-after-free and multi-container gap in kfd_dev_mapping
kfd_dev_mapping caches the address_space of the first /dev/kfd opener
so that the GPU reset path can call unmap_mapping_range() to zap all
userspace mappings of doorbell and MMIO ranges. This design has two
bugs that both manifest under SRIOV with multiple containers:
1. Use-after-free / rwsem deadlock. The cached pointer refers to an
inode owned by the first opener's container. When that container
exits and its inode is released, kfd_dev_mapping becomes a dangling
pointer. A subsequent GPU reset dereferences it inside
unmap_mapping_range(), which takes i_mmap_rwsem on the freed inode,
causing a hard hang observable as an uninterruptible rwsem wait.
2. Multi-container gap. Only the first opener's address_space is cached;
VMAs created by later openers live in a different address_space and
are never reached by unmap_mapping_range(). After a GPU reset those
stale mappings keep doorbell and MMIO pages accessible to guest
userspace with no GPU behind them, risking PCIe transaction timeouts
and NMI panics.
Fix both bugs with the same approach used by DRM core (drm_drv.c):
create a private pseudo-filesystem at module init time and allocate one
anonymous inode from it. In kfd_open() redirect every opener's
file->f_mapping to that inode's address_space. The inode is
module-owned, lives exactly as long as the amdgpu module, and collects
VMAs from all openers in one address_space. A single
unmap_mapping_range() call in the reset path then correctly reaches
every container's mappings with no dangling pointer risk.
The hang manifests as an NMI backtrace on the GPU reset workqueue stuck
spinning in rwsem_down_read_slowpath() with a corrupted i_mmap_rwsem:
Workqueue: amdgpu-reset-dev xgpu_ai_mailbox_flr_work [amdgpu]
Call Trace:
<TASK>
kvm_wait+0x1f/0x40
__pv_queued_spin_lock_slowpath+0x31d/0x3a0
_raw_spin_lock_irq+0x51/0x80
rwsem_down_read_slowpath+0xb3/0x550
down_read+0x48/0xd0
unmap_mapping_range+0x71/0x140
kfd_dev_unmap_mapping_range+0x5b/0x140 [amdgpu]
amdgpu_amdkfd_clear_kfd_mapping+0xd8/0x190 [amdgpu]
amdgpu_device_gpu_recover+0x232/0x450 [amdgpu]
xgpu_ai_mailbox_flr_work+0xb5/0xc0 [amdgpu]
process_one_work+0x18e/0x3e0
worker_thread+0x2e3/0x420
kthread+0x10a/0x230
(cherry picked from commit 1128b4a52de1572e87431de837fd9850cb99542c) |
