| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix divide-by-zero in btf_struct_walk()
When an access goes past the struct and the last member is a flexible
array, btf_struct_walk() folds the offset back into a single element with
(off - moff) % t->size, but never checks that the element type has a size.
BTF takes an empty struct, so this in program BTF
/* event could be empty */
struct event {
#ifdef HAVE_TIMESTAMP
__u64 ts;
#endif
};
struct batch {
int nr;
struct event events[];
};
divides by zero at prog load time. Getting there needs a PTR_TO_BTF_ID that
is not MEM_ALLOC, e.g. a plain read of a local kptr stashed in a map from a
sleepable program.
Oops: divide error: 0000 [#1] SMP KASAN PTI
RIP: 0010:btf_struct_walk+0x53f/0x1570
Call Trace:
<TASK>
btf_struct_access+0x42a/0xcd0
check_ptr_to_btf_access+0x4dc/0x1160
check_mem_access+0x3a45/0x8740
check_load_mem+0x36a/0xd10
do_check_common+0x3ef0/0xb210
bpf_check+0x6d3b/0x8580
bpf_prog_load+0xf7c/0x2720
__sys_bpf+0xa83/0x3690
__x64_sys_bpf+0xc7/0x150
x64_sys_call+0x1f3f/0x27e0
do_syscall_64+0xe5/0x610
entry_SYSCALL_64_after_hwframe+0x76/0x7e
</TASK>
Reject a zero-sized element type. The fixed array path in the same function
already bails out on the same thing:
btf_struct_walk()
...
/* skip empty array */
if (moff == mtrue_end)
continue;
msize /= total_nelems; |
| In the Linux kernel, the following vulnerability has been resolved:
tcp: Skip cond_resched() in inet_csk_listen_stop() under BPF context
bpf_sock_destroy() runs from the tcp iterator, under rcu_read_lock(). If
the sock is a listener that still has children in its accept queue,
tcp_abort() ends up in inet_csk_listen_stop() and the cond_resched()
there trips the debug check:
BUG: sleeping function called from invalid context at net/ipv4/inet_connection_sock.c:1523
in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 628, name: test_progs
preempt_count: 0, expected: 0
RCU nest depth: 1, expected: 0
locks held by test_progs/628: 3, last CPU#3:
#0: ffff8881158cee18 (&p->lock){+.+.}-{4:4}, at: bpf_seq_read+0x56/0x1210
#1: ffff8881106bb858 (sk_lock-AF_INET6){+.+.}-{0:0}, at: bpf_iter_tcp_seq_show+0x32b/0x4b0
#2: ffffffffb435af20 (rcu_read_lock){....}-{1:3}, at: bpf_iter_run_prog+0x46b/0xde0
CPU: 3 UID: 0 PID: 628 Comm: test_progs Tainted: G W 7.2.0+ #65 PREEMPT
Tainted: [W]=WARN
Call Trace:
<TASK>
dump_stack_lvl+0xc1/0xf0
dump_stack+0x10/0x20
__might_resched+0x3d2/0x610
inet_csk_listen_stop+0x7b/0xbf0
tcp_abort+0x23b/0x3b0
bpf_sock_destroy+0xfc/0x140
bpf_prog_448133d24601754f_iter_tcp6_server+0x81/0x8a
bpf_iter_run_prog+0x538/0xde0
bpf_iter_tcp_seq_show+0x26b/0x4b0
bpf_seq_read+0x424/0x1210
vfs_read+0x197/0xe40
ksys_read+0x119/0x240
__x64_sys_read+0x72/0xc0
x64_sys_call+0x647/0x27e0
do_syscall_64+0xe5/0x610
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fad39b28aca
RSP: 002b:00007ffc381c61c0 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007ffc381c6a88 RCX: 00007fad39b28aca
RDX: 0000000000000032 RSI: 00007ffc381c6250 RDI: 0000000000000014
RBP: 00007ffc381c61e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000000000 R14: 000055f077c1bbb0 R15: 00007fad3a0f3000
</TASK>
The commit that added the kfunc already guards lock_sock() in tcp_abort()
and udp_abort() with has_current_bpf_ctx(), but missed the listener path.
Do the same for the cond_resched(). The loop runs inside the iterator's
rcu_read_lock(), it must not reschedule or report a quiescent state there. |
| In the Linux kernel, the following vulnerability has been resolved:
HID: winwing: fix use-after-free in force feedback teardown
winwing_init_ff() passes the driver's private data, allocated with
devm_kzalloc() in winwing_probe(), as the effect context to
input_ff_create_memless(). The memoryless force-feedback core takes
ownership of that pointer and frees it with kfree() from
input_ff_destroy() (ml_ff_destroy()) when the input device is
destroyed.
Freeing a devm-managed allocation with kfree() is an invalid free, and
the same object is then released again by devres when the HID device is
torn down, a double free. As the allocation also embeds the LED class
devices, their timers and work item live on freed memory and the slab
gets corrupted. This triggers on unbind, rmmod, hot-unplug and on system
suspend, where the firmware cache walks the now-corrupt devres list.
KASAN reports:
BUG: KASAN: invalid-free in input_ff_destroy
Allocated by task N:
winwing_probe
Pass NULL as the memless context instead and fetch the driver data from
the input device in winwing_play_effect(): the HID core already stores
the hid_device as the input device's drvdata. The force-feedback core
then owns nothing that it must not free. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Avoid soft lockup in __htab_map_lookup_and_delete_batch()
__htab_map_lookup_and_delete_batch() has no rescheduling point. The
batch count bounds how many entries are copied out, not how many
buckets are visited, so one BPF_MAP_LOOKUP_BATCH call can walk the
map end to end. The empty-bucket fast path is worse: it stays inside
a single rcu_read_lock() / bpf_disable_instrumentation() section for
any run of consecutive empty buckets.
That holds up on small maps, but it falls apart at scale. On a
144-CPU arm64 host running a CONFIG_PREEMPT_NONE kernel, periodic
BPF_MAP_LOOKUP_BATCH calls against an LRU hash map with 16,777,216
buckets held a CPU inside the batch op for 77+ seconds and triggered
the soft lockup watchdog.
Commit 75134f16e7dd ("bpf: Add schedule points in batch ops") fixed this
same problem in the generic batch ops, but not in this htab-native path,
which every htab-based hash map variant uses for its lookup[_and_delete]
batch ops.
Complete that fix here. Leave the critical section after 64 consecutive
empty buckets, call cond_resched_tasks_rcu_qs(), and resume at the saved
bucket cursor. No locks are held at that point, and resuming from the
cursor is already the function's behavior for non-empty buckets. Add the
same call to the per-bucket loop after copy_to_user(), where every lock
has been dropped. cond_resched_rcu() is not enough here: sleeping with
bpf_prog_active elevated makes tracing programs on that CPU silently
skip their invocations.
Plain cond_resched() is not enough either. It is a no-op under PREEMPT
and PREEMPT_LAZY, the only models arm64 and x86 have offered since
commit 7dadeaa6e851 ("sched: Further restrict the preemption modes").
It is also never a Tasks RCU quiescent state, in any model: the
reschedule counts as a preemption. The walking task stays a holdout and
stalls every synchronize_rcu_tasks() caller, ftrace and BPF trampoline
teardown included, until the syscall returns [1].
cond_resched_tasks_rcu_qs() is the usual tool for that [2]. It reports
the quiescent state at each yield and still reschedules as
cond_resched() does on PREEMPT_NONE and PREEMPT_VOLUNTARY kernels. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix out-of-bounds read of rtt_min in sock_ops
A sockops prog reading skops->rtt_min never checks the sk type: on the
tcp_conn_request() path sock_ops->sk is a request_sock (non-full), and the
ctx rewrite casts it to a tcp_sock (full) and reads rtt_min past the end of
the request_sock, returning dirty adjacent memory.
SEC("sockops")
int prog(struct bpf_sock_ops *skops)
{
switch (skops->op) {
case BPF_SOCK_OPS_RWND_INIT:
leak = skops->rtt_min; /* reads the request_sock OOB */
...
}
}
For instance one such read returned rtt_min=0xffff8881, the high half of a
leaked kernel pointer.
Guarding that cast is exactly what SOCK_OPS_GET_FIELD() does -- it checks
is_locked_tcp_sock and returns 0 when sock_ops->sk is not a locked full
socket. Every other tcp_sock field in sock_ops goes through it; rtt_min is
the only one open-coded, so it skips the check.
Read rtt_min through SOCK_OPS_GET_FIELD() too. rtt_min is a bit special:
it is a struct minmax and we only want the current min, so pass
rtt_min.s[0].v. That is equivalent to the old hand-computed offset
offsetof(struct tcp_sock, rtt_min) + sizeof_field(struct minmax_sample, t)
(s[0] sits at rtt_min + 0 and .v at + sizeof(.t), i.e. what minmax_get()
returns), so the loaded field is unchanged and only the full-sock guard is
added. The two BUILD_BUG_ON()s that protected the hand-computed offset
are no longer needed.
Before patch:
0: r1 = *(u64 *)(r1 +0) ; r1 = skops->sk
1: r1 = *(u32 *)(r1 +2324) ; ((tcp_sock *)sk)->rtt_min.s[0].v
After patch:
0: *(u64 *)(r1 +56) = r9
1: r9 = *(u8 *)(r1 +50) ; is_locked_tcp_sock
2: if r9 == 0 goto pc+4 ; not a locked full sock -> 0
3: r9 = *(u64 *)(r1 +56)
4: r1 = *(u64 *)(r1 +0) ; r1 = skops->sk
5: r1 = *(u32 *)(r1 +2324) ; rtt_min.s[0].v
6: goto pc+2
7: r9 = *(u64 *)(r1 +56)
8: r1 = 0 |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix UAF due to concurrent consumption of ttrace lists in alloc_bulk
Syzkaller repeatedly triggered UAF splats related to nodes in
waiting_for_gp_ttrace within the bpf memalloc:
BUG: KASAN: slab-use-after-free in llist_del_first+0x85/0x110 lib/llist.c:61
Read of size 8 at addr ffff8881572cd080 by task syz.4.470/5112
...
llist_del_first+0x85/0x110 lib/llist.c:61
alloc_bulk+0x193/0x460 kernel/bpf/memalloc.c:229
bpf_mem_refill+0x386/0x560 kernel/bpf/memalloc.c:436
Freed by task 14:
...
__free_rcu kernel/bpf/memalloc.c:281 [inline]
__free_rcu_tasks_trace+0x48/0xd0 kernel/bpf/memalloc.c:291
rcu_tasks_invoke_cbs+0x1ec/0x3e0 kernel/rcu/tasks.h:571
rcu_tasks_one_gp+0x13d/0x220 kernel/rcu/tasks.h:621
rcu_tasks_kthread+0xf3/0x120 kernel/rcu/tasks.h:651
The reason is that the UAF occurs after the RCU Tasks Trace GP expires:
when the __free_rcu() callback runs, there is no synchronization
protecting llist_del_all() against concurrent alloc_bulk() operating on
waiting_for_gp_ttrace, leading to the race condition below:
CPU0 CPU1
__free_rcu (RCU Tasks Trace callback)
alloc_bulk
llist_del_first(&c->waiting_for_gp_ttrace)
entry = smp_load_acquire(&head->first);
do {
if (entry == NULL)
return NULL;
free_all(llist_del_all(&c->waiting_for_gp_ttrace))
llist_for_each_safe(pos, t, llnode)
free_one(pos);
next = READ_ONCE(entry->next); <-- trigger UAF
} while (!try_cmpxchg(&head->first, &entry, next));
In addition, there is also a theoretical race condition on the
free_by_rcu_ttrace list. This race requires two preconditions: an
in-flight Tasks Trace GP keeping c->call_rcu_ttrace_in_progress == 1,
and concurrent cross-CPU frees repopulating c->free_by_rcu_ttrace with
new nodes. Under these conditions, the following scenario triggers UAF:
// CPU0
// irq work is still busy (on PREEMPT_RT)
alloc_bulk()
llist_del_first(&c->free_by_rcu_ttrace)
entry = smp_load_acquire(&head->first);
do {
if (entry == NULL)
return NULL;
// CPU1
bpf_mem_alloc_destroy()
WRITE_ONCE(c->draining, true)
// wait for CPU0
irq_work_sync()
// CPU2
do_call_rcu_ttrace(tgt(CPU0))
if (c->draining) {
llist_del_all(&c->free_by_rcu_ttrace)
free_all()
}
// CPU0 continue
next = READ_ONCE(entry->next); <-- trigger UAF
while (!try_cmpxchg(&head->first, &entry, next));
Fix this by introducing a raw spinlock to synchronize the concurrent
consumption on waiting_for_gp_ttrace and free_by_rcu_ttrace. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf, arm64: set up the frame pointer for the exception callback
A program acting as exception boundary saves all callee-saved registers,
so build_prologue() takes the exception_cb path and never calls
push_callee_regs(). That is the only place find_used_callee_regs() runs,
and with it the only place ctx->fp_used is set, so the callback prologue
does not emit the
mov x25, sp
that points BPF_REG_FP at the frame the callback runs on. x25 keeps
whatever it held when bpf_throw() was called. If the throw came from a
subprogram that uses its own BPF stack, that is the subprogram's frame
pointer, and since the subprogram never returns it never restores x25
either.
Stack accesses through BPF_REG_FP are rewritten to be stack pointer
relative, so those still land in the callback's own frame. Materializing
the register does not: a callback that passes the address of a local
variable to a helper hands over an address in the dead subprogram's
frame. That address is below the callback's stack pointer by then, and
the helper's own call chain covers it, so the helper can write over its
own return address. 0x1234 below is the value the helper was asked to
store:
pc : 0x1234
lr : 0x1234
Call trace:
0x1234 (P)
bpf_test_run+0x188/0x3e0
bpf_prog_test_run_skb+0x47c/0x998
__sys_bpf+0xbdc/0xdd8
Kernel panic - not syncing: Oops: Fatal exception in interrupt
Set ctx->fp_used on the exception callback path so that the existing code
further down sets x25 from the stack pointer. The epilogue restores it
from the main program's save area along with the other callee-saved
registers, as it already does. x86 sets the frame pointer for the
callback from the argument it is passed, and powerpc computes it from
the stack pointer. |
| In the Linux kernel, the following vulnerability has been resolved:
HID: amd_sfh: Validate PCI BAR size before mapping
The amd_sfh driver maps PCI BAR 2 using pcim_iomap_regions() and
subsequently accesses MMIO registers at offsets up to 0x10958 (e.g.,
AMD_P2C_MSG3 at 0x1068C). However, the driver never validates that the BAR
size is large enough to cover these accesses. If the driver is bound to a
device with a smaller BAR 2, this leads to an out-of-bounds memory access
and a page fault during the probe function.
For example, a page fault can occur when reading from privdata->mmio +
AMD_P2C_MSG3 in mp2_select_ops():
BUG: unable to handle page fault for address: ffffc9000390368c
PGD 100000067 P4D 100000067 PUD 1012c1067 PMD 105b64067 PTE 0
Oops: Oops: 0000 [#1] SMP KASAN NOPTI
RIP: 0010:readl arch/x86/include/asm/io.h:59 [inline]
RIP: 0010:mp2_select_ops drivers/hid/amd-sfh-hid/amd_sfh_pcie.c:282
[inline]
RIP: 0010:amd_mp2_pci_probe+0x337/0x5f0
drivers/hid/amd-sfh-hid/amd_sfh_pcie.c:487
Call Trace:
<TASK>
local_pci_probe drivers/pci/pci-driver.c:332 [inline]
pci_call_probe drivers/pci/pci-driver.c:394 [inline]
__pci_device_probe drivers/pci/pci-driver.c:455 [inline]
pci_device_probe+0x431/0xc90 drivers/pci/pci-driver.c:489
Fix this by verifying that the length of BAR 2 is at least 128KB before
attempting to map it. Since the maximum accessed offset is 0x10958, and PCI
BAR sizes are powers of 2, any legitimate hardware will have a BAR size of
at least 128KB. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: riscv: Fix NACL hfence entry update order
The SBI v3.0 specification (section 15.1.2) requires a nested HFENCE
entry to be populated as follows:
1) find an unused entry with Config.Pending == 0
2) update the Page_Number and Page_Count words
3) update the Config word with Config.Pending set
__kvm_riscv_nacl_hfence() writes the Config word first, so the SBI
implementation (or NACL hardware) can observe a pending entry with
pnum/pcount values left over from the previous use of that entry,
resulting in incorrect TLB flush ranges.
Write pnum and pcount first and the Config word last. Since the
consumer is an external agent on coherent shared memory, use
WRITE_ONCE() to stop the compiler from reordering the stores and
smp_wmb() to make the parameter words globally visible before the
Pending bit is set. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: Validate the SVE vector length in pkvm_vcpu_init_sve()
pkvm_vcpu_init_sve() clamps only the upper bound of the host-provided
sve_max_vl, so an invalid vector length reaches sve_state_size_from_vl()
and the WARN_ON() there, which is fatal at EL2. The existing
!sve_state_size test rejects such a length, but only after the macro has
run.
Check sve_vl_valid() before deriving the state size. A valid length
cannot yield a zero size, so the !sve_state_size test goes with it. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: Do not clear VM-wide SVE feature on vCPU init failure
pkvm_vcpu_init_sve() clears KVM_ARM_VCPU_SVE in kvm->arch.vcpu_features
when it fails, but vcpu_has_sve() tests KVM_ARCH_FLAG_GUEST_HAS_SVE,
which is left set. Later vCPUs on that VM then skip the SVE setup and
register with a NULL sve_state, which the guest's first FP access hands
to sve_load_state().
Return the error without touching vcpu_features. |
| In the Linux kernel, the following vulnerability has been resolved:
squashfs: Add dictionary size range check to prevent shift-out-of-bounds
When an abnormal SquashFS image (COMP_OPTS flag is 1 but dictionary size
is 0) is mounted, and performs shift operations using dictionarysize, the
shift exponent is -1, causing a shift-out-of-bounds.
Detail as below:
squashfs_comp_opts(msblk, buffer, length)
squashfs_xz_comp_opts()
if (comp_opts)
n = ffs(opts->dict_size) - 1;<----opts->dict_size=0, n=-1
if (opts->dict_size != (1 << n) && opts->dict_size !=
(1 << n) + (1 << (n + 1))) <----shift-out-of-bounds
Fix it by adding a dictionary size range check before the shift operation. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: block: Fix zones_cond out-of-bounds write on zone report
blk_revalidate_disk_zones() sizes the zones_cond array from the disk
capacity and zone size, but the index used by blk_revalidate_zone_cond()
comes from the device-driven report_zones() walk and is never checked
against the array size. A device reporting more zones than fit the array
makes blk_zone_set_cond() write out of bounds.
One way to reach this is a zone count exceeding 32 bits: both
blk_revalidate_zone_args.nr_zones and struct zoned_disk_info.nr_zones are
unsigned int, so a disk advertising more than UINT_MAX zones (e.g. 2^32 +
1024 zones of one 512-byte logical block) gets its zone count truncated to
a small value, undersizing the array while the report walk keeps counting
upward.
Check the index against the array size before storing the zone condition,
and refuse to revalidate when the zone count does not fit 32 bits. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: sd_zbc: Reject disks with too many zones
sd_zbc_read_zones() computes the number of zones with 64-bit arithmetic and
stores the result in the unsigned int nr_zones field of struct
zoned_disk_info, silently truncating counts that exceed 32 bits. The
truncated count is later used to size per-zone resources, while the device
may still report more zones than fit.
Moreover, sd_zbc_report_zones() counts the reported zones with a signed int
zone_idx, which overflows past INT_MAX. Reject devices reporting more than
INT_MAX zones at scan time; such a device is not realistic for any medium
that exists today, and accepting it produces inconsistent zone bookkeeping. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: btnxpuart: Fix skb leak in nxp_process_fw_dump()
When CONFIG_DEV_COREDUMP=n, hci_devcd_append() returns -EOPNOTSUPP
without freeing its skb argument. This leaks the cloned skb and also
prevents nxp_set_ind_reset() from being called to perform recovery.
Fix by guarding the hci_devcd_append(hdev, skb_clone(skb, GFP_ATOMIC))
call with IS_ENABLED(CONFIG_DEV_COREDUMP). |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: mgmt: Dequeue pending mesh_send_sync entries on cancel
In send_cancel(), pending mesh_tx objects are removed from the
hdev->mesh_pending list and freed via mesh_send_complete(). However, if
a mesh transmission was already queued onto hdev->cmd_sync_work_list via
mesh_next(), the queued entry retains a raw pointer to mesh_tx.
When hci_cmd_sync_work later processes the entry, it attempts to execute
mesh_send_sync and its destroy callback mesh_send_start_complete using
the already freed mesh_tx pointer, leading to a use-after-free.
Fix this by invoking hci_cmd_sync_dequeue() for mesh_send_sync on the
target mesh_tx before completing it. If the entry is found and dequeued,
its destroy callback will complete and free the object; otherwise,
mesh_send_complete() is called directly.
Additionally, ensure the transmission queue advances after cancellation
or errors. In mesh_send_start_complete(), call mesh_next() on error
unless err is -ECANCELED, because hci_cmd_sync_dequeue() holds
hdev->cmd_sync_work_lock and calling mesh_next() synchronously would
deadlock. Instead, advance the queue in send_cancel() once the lock is
released and if no transmission is in progress. |
| In the Linux kernel, the following vulnerability has been resolved:
xsk: Use a 32-bit compare in xsk_map_gen_lookup
xsk_map_gen_lookup() loads a u32 key and compares it with max_entries
using BPF_JMP_IMM. BPF immediates are sign-extended to 64 bits, so a
max_entries value of 0x80000000 or higher becomes a threshold larger
than every zero-extended 32-bit key. An out-of-range index then skips
the bounds check and the generated lookup reads past xsk_map[].
Compare with BPF_JMP32_IMM so the check stays in 32-bit unsigned range. |
| In the Linux kernel, the following vulnerability has been resolved:
eth: fbnic: Fix payload page pool error cleanup
The payload page pool pointer contains an error pointer when its
allocation fails. The cleanup path passes that error pointer to
page_pool_destroy() instead of destroying the header page pool. This
can dereference the error pointer and leave the header page pool
allocated.
Destroy the header page pool instead. |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: cls_u32: fix manual hash table handle IDR aliasing
A u32 hash table created with an explicit handle ('tc filter add ...
handle 801: u32 divisor N') keys its IDR entry on the raw handle, while
the destroy paths free it under handle2id(handle). The two key domains
disagree for handles in the 0x800..0xFFF htid range:
handle2id() folds them back into the auto-allocated id space (1..0x7FF).
A manual table therefore leaves its raw-keyed IDR entry unreachable on
delete (a permanent leak), and its delete can drop the idr entry of an
unrelated live auto table. A later auto allocation can then hand out a
handle that aliases the live manual table; u32_lookup_ht() first-match
routes lookups and TCA_U32_LINK for that htid to the wrong table.
Key the divisor-path alloc on handle2id(handle) so allocation and
removal share one key domain. A manual handle that maps onto an id
already in use is rejected with -ENOSPC, and auto allocation skips ids
held by live manual tables.
Conditions to recreate:
ip link add test0 type dummy
tc qdisc add dev test0 clsact
tc filter add dev test0 ingress protocol ip pref 1 \
handle 801: u32 divisor 16
tc filter add dev test0 ingress protocol ip pref 2 u32 divisor 16
tc -d filter show dev test0 ingress | grep 'fh 801:'
# unpatched: two live tables with handle 0x80100000 (the pref 2 root
# hnode is auto-allocated id 1); patched: the auto hnode takes id 2.
Also tested with a poc with a live u32 table on the block, add/delete a manual
table 'handle 901: u32 divisor 1' twice; unpatched, the re-add fails with
-ENOSPC because the raw key leaked on the first delete. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Make post-verification instruction rewrites killable
After do_check() returns, the verifier runs several instruction rewrite
passes. Some of them patch or remove one instruction at a time. Each
operation moves the remaining instruction and auxiliary-data arrays and
adjusts all branch offsets, making the overall work quadratic in the
program length.
A privileged loader can submit 131072 unconditional jumps by zero followed
by a valid return. Verification finishes quickly, but bpf_opt_remove_nops()
then spends a long time removing each jump separately. Since this
post-verification work neither checks for signals nor reschedules, a pending
SIGKILL cannot terminate the task until the rewrite finishes.
Make bpf_patch_insn_data() and verifier_remove_insns() common cancellation
and rescheduling points. These helpers run from BPF_PROG_LOAD process
context, and bpf_patch_insn_data() can already sleep while reallocating
auxiliary data.
Report interrupted constant blinding as -EINTR and propagate it through
both JIT paths, including kernels that permit interpreter fallback.
Other blinding failures retain the existing fallback behavior.
This does not reduce the quadratic cost of the rewrite passes, but it makes
the work preemptible and allows a killed loader to be torn down promptly. |
