| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: Unconditionally save+flush host FPSIMD/SVE/SME state
There are several problems with the way hyp code lazily saves the host's
FPSIMD/SVE state, including:
* Host SVE being discarded unexpectedly due to inconsistent
configuration of TIF_SVE and CPACR_ELx.ZEN. This has been seen to
result in QEMU crashes where SVE is used by memmove(), as reported by
Eric Auger:
https://issues.redhat.com/browse/RHEL-68997
* Host SVE state is discarded *after* modification by ptrace, which was an
unintentional ptrace ABI change introduced with lazy discarding of SVE state.
* The host FPMR value can be discarded when running a non-protected VM,
where FPMR support is not exposed to a VM, and that VM uses
FPSIMD/SVE. In these cases the hyp code does not save the host's FPMR
before unbinding the host's FPSIMD/SVE/SME state, leaving a stale
value in memory.
Avoid these by eagerly saving and "flushing" the host's FPSIMD/SVE/SME
state when loading a vCPU such that KVM does not need to save any of the
host's FPSIMD/SVE/SME state. For clarity, fpsimd_kvm_prepare() is
removed and the necessary call to fpsimd_save_and_flush_cpu_state() is
placed in kvm_arch_vcpu_load_fp(). As 'fpsimd_state' and 'fpmr_ptr'
should not be used, they are set to NULL; all uses of these will be
removed in subsequent patches.
Historical problems go back at least as far as v5.17, e.g. erroneous
assumptions about TIF_SVE being clear in commit:
8383741ab2e773a9 ("KVM: arm64: Get rid of host SVE tracking/saving")
... and so this eager save+flush probably needs to be backported to ALL
stable trees. |
| In the Linux kernel, the following vulnerability has been resolved:
idpf: fix checksums set in idpf_rx_rsc()
idpf_rx_rsc() uses skb_transport_offset(skb) while the transport header
is not set yet.
This triggers the following warning for CONFIG_DEBUG_NET=y builds.
DEBUG_NET_WARN_ON_ONCE(!skb_transport_header_was_set(skb))
[ 69.261620] WARNING: CPU: 7 PID: 0 at ./include/linux/skbuff.h:3020 idpf_vport_splitq_napi_poll (include/linux/skbuff.h:3020) idpf
[ 69.261629] Modules linked in: vfat fat dummy bridge intel_uncore_frequency_tpmi intel_uncore_frequency_common intel_vsec_tpmi idpf intel_vsec cdc_ncm cdc_eem cdc_ether usbnet mii xhci_pci xhci_hcd ehci_pci ehci_hcd libeth
[ 69.261644] CPU: 7 UID: 0 PID: 0 Comm: swapper/7 Tainted: G S W 6.14.0-smp-DEV #1697
[ 69.261648] Tainted: [S]=CPU_OUT_OF_SPEC, [W]=WARN
[ 69.261650] RIP: 0010:idpf_vport_splitq_napi_poll (include/linux/skbuff.h:3020) idpf
[ 69.261677] ? __warn (kernel/panic.c:242 kernel/panic.c:748)
[ 69.261682] ? idpf_vport_splitq_napi_poll (include/linux/skbuff.h:3020) idpf
[ 69.261687] ? report_bug (lib/bug.c:?)
[ 69.261690] ? handle_bug (arch/x86/kernel/traps.c:285)
[ 69.261694] ? exc_invalid_op (arch/x86/kernel/traps.c:309)
[ 69.261697] ? asm_exc_invalid_op (arch/x86/include/asm/idtentry.h:621)
[ 69.261700] ? __pfx_idpf_vport_splitq_napi_poll (drivers/net/ethernet/intel/idpf/idpf_txrx.c:4011) idpf
[ 69.261704] ? idpf_vport_splitq_napi_poll (include/linux/skbuff.h:3020) idpf
[ 69.261708] ? idpf_vport_splitq_napi_poll (drivers/net/ethernet/intel/idpf/idpf_txrx.c:3072) idpf
[ 69.261712] __napi_poll (net/core/dev.c:7194)
[ 69.261716] net_rx_action (net/core/dev.c:7265)
[ 69.261718] ? __qdisc_run (net/sched/sch_generic.c:293)
[ 69.261721] ? sched_clock (arch/x86/include/asm/preempt.h:84 arch/x86/kernel/tsc.c:288)
[ 69.261726] handle_softirqs (kernel/softirq.c:561) |
| In the Linux kernel, the following vulnerability has been resolved:
perf/core: Add RCU read lock protection to perf_iterate_ctx()
The perf_iterate_ctx() function performs RCU list traversal but
currently lacks RCU read lock protection. This causes lockdep warnings
when running perf probe with unshare(1) under CONFIG_PROVE_RCU_LIST=y:
WARNING: suspicious RCU usage
kernel/events/core.c:8168 RCU-list traversed in non-reader section!!
Call Trace:
lockdep_rcu_suspicious
? perf_event_addr_filters_apply
perf_iterate_ctx
perf_event_exec
begin_new_exec
? load_elf_phdrs
load_elf_binary
? lock_acquire
? find_held_lock
? bprm_execve
bprm_execve
do_execveat_common.isra.0
__x64_sys_execve
do_syscall_64
entry_SYSCALL_64_after_hwframe
This protection was previously present but was removed in commit
bd2756811766 ("perf: Rewrite core context handling"). Add back the
necessary rcu_read_lock()/rcu_read_unlock() pair around
perf_iterate_ctx() call in perf_event_exec().
[ mingo: Use scoped_guard() as suggested by Peter ] |
| In the Linux kernel, the following vulnerability has been resolved:
net: better track kernel sockets lifetime
While kernel sockets are dismantled during pernet_operations->exit(),
their freeing can be delayed by any tx packets still held in qdisc
or device queues, due to skb_set_owner_w() prior calls.
This then trigger the following warning from ref_tracker_dir_exit() [1]
To fix this, make sure that kernel sockets own a reference on net->passive.
Add sk_net_refcnt_upgrade() helper, used whenever a kernel socket
is converted to a refcounted one.
[1]
[ 136.263918][ T35] ref_tracker: net notrefcnt@ffff8880638f01e0 has 1/2 users at
[ 136.263918][ T35] sk_alloc+0x2b3/0x370
[ 136.263918][ T35] inet6_create+0x6ce/0x10f0
[ 136.263918][ T35] __sock_create+0x4c0/0xa30
[ 136.263918][ T35] inet_ctl_sock_create+0xc2/0x250
[ 136.263918][ T35] igmp6_net_init+0x39/0x390
[ 136.263918][ T35] ops_init+0x31e/0x590
[ 136.263918][ T35] setup_net+0x287/0x9e0
[ 136.263918][ T35] copy_net_ns+0x33f/0x570
[ 136.263918][ T35] create_new_namespaces+0x425/0x7b0
[ 136.263918][ T35] unshare_nsproxy_namespaces+0x124/0x180
[ 136.263918][ T35] ksys_unshare+0x57d/0xa70
[ 136.263918][ T35] __x64_sys_unshare+0x38/0x40
[ 136.263918][ T35] do_syscall_64+0xf3/0x230
[ 136.263918][ T35] entry_SYSCALL_64_after_hwframe+0x77/0x7f
[ 136.263918][ T35]
[ 136.343488][ T35] ref_tracker: net notrefcnt@ffff8880638f01e0 has 1/2 users at
[ 136.343488][ T35] sk_alloc+0x2b3/0x370
[ 136.343488][ T35] inet6_create+0x6ce/0x10f0
[ 136.343488][ T35] __sock_create+0x4c0/0xa30
[ 136.343488][ T35] inet_ctl_sock_create+0xc2/0x250
[ 136.343488][ T35] ndisc_net_init+0xa7/0x2b0
[ 136.343488][ T35] ops_init+0x31e/0x590
[ 136.343488][ T35] setup_net+0x287/0x9e0
[ 136.343488][ T35] copy_net_ns+0x33f/0x570
[ 136.343488][ T35] create_new_namespaces+0x425/0x7b0
[ 136.343488][ T35] unshare_nsproxy_namespaces+0x124/0x180
[ 136.343488][ T35] ksys_unshare+0x57d/0xa70
[ 136.343488][ T35] __x64_sys_unshare+0x38/0x40
[ 136.343488][ T35] do_syscall_64+0xf3/0x230
[ 136.343488][ T35] entry_SYSCALL_64_after_hwframe+0x77/0x7f |
| In the Linux kernel, the following vulnerability has been resolved:
iommu/vt-d: Fix suspicious RCU usage
Commit <d74169ceb0d2> ("iommu/vt-d: Allocate DMAR fault interrupts
locally") moved the call to enable_drhd_fault_handling() to a code
path that does not hold any lock while traversing the drhd list. Fix
it by ensuring the dmar_global_lock lock is held when traversing the
drhd list.
Without this fix, the following warning is triggered:
=============================
WARNING: suspicious RCU usage
6.14.0-rc3 #55 Not tainted
-----------------------------
drivers/iommu/intel/dmar.c:2046 RCU-list traversed in non-reader section!!
other info that might help us debug this:
rcu_scheduler_active = 1, debug_locks = 1
2 locks held by cpuhp/1/23:
#0: ffffffff84a67c50 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x87/0x2c0
#1: ffffffff84a6a380 (cpuhp_state-up){+.+.}-{0:0}, at: cpuhp_thread_fun+0x87/0x2c0
stack backtrace:
CPU: 1 UID: 0 PID: 23 Comm: cpuhp/1 Not tainted 6.14.0-rc3 #55
Call Trace:
<TASK>
dump_stack_lvl+0xb7/0xd0
lockdep_rcu_suspicious+0x159/0x1f0
? __pfx_enable_drhd_fault_handling+0x10/0x10
enable_drhd_fault_handling+0x151/0x180
cpuhp_invoke_callback+0x1df/0x990
cpuhp_thread_fun+0x1ea/0x2c0
smpboot_thread_fn+0x1f5/0x2e0
? __pfx_smpboot_thread_fn+0x10/0x10
kthread+0x12a/0x2d0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x4a/0x60
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
Holding the lock in enable_drhd_fault_handling() triggers a lockdep splat
about a possible deadlock between dmar_global_lock and cpu_hotplug_lock.
This is avoided by not holding dmar_global_lock when calling
iommu_device_register(), which initiates the device probe process. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Load DR6 with guest value only before entering .vcpu_run() loop
Move the conditional loading of hardware DR6 with the guest's DR6 value
out of the core .vcpu_run() loop to fix a bug where KVM can load hardware
with a stale vcpu->arch.dr6.
When the guest accesses a DR and host userspace isn't debugging the guest,
KVM disables DR interception and loads the guest's values into hardware on
VM-Enter and saves them on VM-Exit. This allows the guest to access DRs
at will, e.g. so that a sequence of DR accesses to configure a breakpoint
only generates one VM-Exit.
For DR0-DR3, the logic/behavior is identical between VMX and SVM, and also
identical between KVM_DEBUGREG_BP_ENABLED (userspace debugging the guest)
and KVM_DEBUGREG_WONT_EXIT (guest using DRs), and so KVM handles loading
DR0-DR3 in common code, _outside_ of the core kvm_x86_ops.vcpu_run() loop.
But for DR6, the guest's value doesn't need to be loaded into hardware for
KVM_DEBUGREG_BP_ENABLED, and SVM provides a dedicated VMCB field whereas
VMX requires software to manually load the guest value, and so loading the
guest's value into DR6 is handled by {svm,vmx}_vcpu_run(), i.e. is done
_inside_ the core run loop.
Unfortunately, saving the guest values on VM-Exit is initiated by common
x86, again outside of the core run loop. If the guest modifies DR6 (in
hardware, when DR interception is disabled), and then the next VM-Exit is
a fastpath VM-Exit, KVM will reload hardware DR6 with vcpu->arch.dr6 and
clobber the guest's actual value.
The bug shows up primarily with nested VMX because KVM handles the VMX
preemption timer in the fastpath, and the window between hardware DR6
being modified (in guest context) and DR6 being read by guest software is
orders of magnitude larger in a nested setup. E.g. in non-nested, the
VMX preemption timer would need to fire precisely between #DB injection
and the #DB handler's read of DR6, whereas with a KVM-on-KVM setup, the
window where hardware DR6 is "dirty" extends all the way from L1 writing
DR6 to VMRESUME (in L1).
L1's view:
==========
<L1 disables DR interception>
CPU 0/KVM-7289 [023] d.... 2925.640961: kvm_entry: vcpu 0
A: L1 Writes DR6
CPU 0/KVM-7289 [023] d.... 2925.640963: <hack>: Set DRs, DR6 = 0xffff0ff1
B: CPU 0/KVM-7289 [023] d.... 2925.640967: kvm_exit: vcpu 0 reason EXTERNAL_INTERRUPT intr_info 0x800000ec
D: L1 reads DR6, arch.dr6 = 0
CPU 0/KVM-7289 [023] d.... 2925.640969: <hack>: Sync DRs, DR6 = 0xffff0ff0
CPU 0/KVM-7289 [023] d.... 2925.640976: kvm_entry: vcpu 0
L2 reads DR6, L1 disables DR interception
CPU 0/KVM-7289 [023] d.... 2925.640980: kvm_exit: vcpu 0 reason DR_ACCESS info1 0x0000000000000216
CPU 0/KVM-7289 [023] d.... 2925.640983: kvm_entry: vcpu 0
CPU 0/KVM-7289 [023] d.... 2925.640983: <hack>: Set DRs, DR6 = 0xffff0ff0
L2 detects failure
CPU 0/KVM-7289 [023] d.... 2925.640987: kvm_exit: vcpu 0 reason HLT
L1 reads DR6 (confirms failure)
CPU 0/KVM-7289 [023] d.... 2925.640990: <hack>: Sync DRs, DR6 = 0xffff0ff0
L0's view:
==========
L2 reads DR6, arch.dr6 = 0
CPU 23/KVM-5046 [001] d.... 3410.005610: kvm_exit: vcpu 23 reason DR_ACCESS info1 0x0000000000000216
CPU 23/KVM-5046 [001] ..... 3410.005610: kvm_nested_vmexit: vcpu 23 reason DR_ACCESS info1 0x0000000000000216
L2 => L1 nested VM-Exit
CPU 23/KVM-5046 [001] ..... 3410.005610: kvm_nested_vmexit_inject: reason: DR_ACCESS ext_inf1: 0x0000000000000216
CPU 23/KVM-5046 [001] d.... 3410.005610: kvm_entry: vcpu 23
CPU 23/KVM-5046 [001] d.... 3410.005611: kvm_exit: vcpu 23 reason VMREAD
CPU 23/KVM-5046 [001] d.... 3410.005611: kvm_entry: vcpu 23
CPU 23/KVM-5046 [001] d.... 3410.
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
io_uring/kbuf: reallocate buf lists on upgrade
IORING_REGISTER_PBUF_RING can reuse an old struct io_buffer_list if it
was created for legacy selected buffer and has been emptied. It violates
the requirement that most of the field should stay stable after publish.
Always reallocate it instead. |
| In the Linux kernel, the following vulnerability has been resolved:
block: don't revert iter for -EIOCBQUEUED
blkdev_read_iter() has a few odd checks, like gating the position and
count adjustment on whether or not the result is bigger-than-or-equal to
zero (where bigger than makes more sense), and not checking the return
value of blkdev_direct_IO() before doing an iov_iter_revert(). The
latter can lead to attempting to revert with a negative value, which
when passed to iov_iter_revert() as an unsigned value will lead to
throwing a WARN_ON() because unroll is bigger than MAX_RW_COUNT.
Be sane and don't revert for -EIOCBQUEUED, like what is done in other
spots. |
| In the Linux kernel, the following vulnerability has been resolved:
landlock: Handle weird files
A corrupted filesystem (e.g. bcachefs) might return weird files.
Instead of throwing a warning and allowing access to such file, treat
them as regular files. |
| In the Linux kernel, the following vulnerability has been resolved:
net: xdp: Disallow attaching device-bound programs in generic mode
Device-bound programs are used to support RX metadata kfuncs. These
kfuncs are driver-specific and rely on the driver context to read the
metadata. This means they can't work in generic XDP mode. However, there
is no check to disallow such programs from being attached in generic
mode, in which case the metadata kfuncs will be called in an invalid
context, leading to crashes.
Fix this by adding a check to disallow attaching device-bound programs
in generic mode. |
| In the Linux kernel, the following vulnerability has been resolved:
ipv4: use RCU protection in __ip_rt_update_pmtu()
__ip_rt_update_pmtu() must use RCU protection to make
sure the net structure it reads does not disappear. |
| In the Linux kernel, the following vulnerability has been resolved:
md/md-bitmap: Synchronize bitmap_get_stats() with bitmap lifetime
After commit ec6bb299c7c3 ("md/md-bitmap: add 'sync_size' into struct
md_bitmap_stats"), following panic is reported:
Oops: general protection fault, probably for non-canonical address
RIP: 0010:bitmap_get_stats+0x2b/0xa0
Call Trace:
<TASK>
md_seq_show+0x2d2/0x5b0
seq_read_iter+0x2b9/0x470
seq_read+0x12f/0x180
proc_reg_read+0x57/0xb0
vfs_read+0xf6/0x380
ksys_read+0x6c/0xf0
do_syscall_64+0x82/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Root cause is that bitmap_get_stats() can be called at anytime if mddev
is still there, even if bitmap is destroyed, or not fully initialized.
Deferenceing bitmap in this case can crash the kernel. Meanwhile, the
above commit start to deferencing bitmap->storage, make the problem
easier to trigger.
Fix the problem by protecting bitmap_get_stats() with bitmap_info.mutex. |
| In the Linux kernel, the following vulnerability has been resolved:
kernel: be more careful about dup_mmap() failures and uprobe registering
If a memory allocation fails during dup_mmap(), the maple tree can be left
in an unsafe state for other iterators besides the exit path. All the
locks are dropped before the exit_mmap() call (in mm/mmap.c), but the
incomplete mm_struct can be reached through (at least) the rmap finding
the vmas which have a pointer back to the mm_struct.
Up to this point, there have been no issues with being able to find an
mm_struct that was only partially initialised. Syzbot was able to make
the incomplete mm_struct fail with recent forking changes, so it has been
proven unsafe to use the mm_struct that hasn't been initialised, as
referenced in the link below.
Although 8ac662f5da19f ("fork: avoid inappropriate uprobe access to
invalid mm") fixed the uprobe access, it does not completely remove the
race.
This patch sets the MMF_OOM_SKIP to avoid the iteration of the vmas on the
oom side (even though this is extremely unlikely to be selected as an oom
victim in the race window), and sets MMF_UNSTABLE to avoid other potential
users from using a partially initialised mm_struct.
When registering vmas for uprobe, skip the vmas in an mm that is marked
unstable. Modifying a vma in an unstable mm may cause issues if the mm
isn't fully initialised. |
| In the Linux kernel, the following vulnerability has been resolved:
dm thin: make get_first_thin use rcu-safe list first function
The documentation in rculist.h explains the absence of list_empty_rcu()
and cautions programmers against relying on a list_empty() ->
list_first() sequence in RCU safe code. This is because each of these
functions performs its own READ_ONCE() of the list head. This can lead
to a situation where the list_empty() sees a valid list entry, but the
subsequent list_first() sees a different view of list head state after a
modification.
In the case of dm-thin, this author had a production box crash from a GP
fault in the process_deferred_bios path. This function saw a valid list
head in get_first_thin() but when it subsequently dereferenced that and
turned it into a thin_c, it got the inside of the struct pool, since the
list was now empty and referring to itself. The kernel on which this
occurred printed both a warning about a refcount_t being saturated, and
a UBSAN error for an out-of-bounds cpuid access in the queued spinlock,
prior to the fault itself. When the resulting kdump was examined, it
was possible to see another thread patiently waiting in thin_dtr's
synchronize_rcu.
The thin_dtr call managed to pull the thin_c out of the active thins
list (and have it be the last entry in the active_thins list) at just
the wrong moment which lead to this crash.
Fortunately, the fix here is straight forward. Switch get_first_thin()
function to use list_first_or_null_rcu() which performs just a single
READ_ONCE() and returns NULL if the list is already empty.
This was run against the devicemapper test suite's thin-provisioning
suites for delete and suspend and no regressions were observed. |
| In the Linux kernel, the following vulnerability has been resolved:
tls: stop recv() if initial process_rx_list gave us non-DATA
If we have a non-DATA record on the rx_list and another record of the
same type still on the queue, we will end up merging them:
- process_rx_list copies the non-DATA record
- we start the loop and process the first available record since it's
of the same type
- we break out of the loop since the record was not DATA
Just check the record type and jump to the end in case process_rx_list
did some work. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: btnxpuart: Resolve TX timeout error in power save stress test
This fixes the tx timeout issue seen while running a stress test on
btnxpuart for couple of hours, such that the interval between two HCI
commands coincide with the power save timeout value of 2 seconds.
Test procedure using bash script:
<load btnxpuart.ko>
hciconfig hci0 up
//Enable Power Save feature
hcitool -i hci0 cmd 3f 23 02 00 00
while (true)
do
hciconfig hci0 leadv
sleep 2
hciconfig hci0 noleadv
sleep 2
done
Error log, after adding few more debug prints:
Bluetooth: btnxpuart_queue_skb(): 01 0A 20 01 00
Bluetooth: hci0: Set UART break: on, status=0
Bluetooth: hci0: btnxpuart_tx_wakeup() tx_work scheduled
Bluetooth: hci0: btnxpuart_tx_work() dequeue: 01 0A 20 01 00
Can't set advertise mode on hci0: Connection timed out (110)
Bluetooth: hci0: command 0x200a tx timeout
When the power save mechanism turns on UART break, and btnxpuart_tx_work()
is scheduled simultaneously, psdata->ps_state is read as PS_STATE_AWAKE,
which prevents the psdata->work from being scheduled, which is responsible
to turn OFF UART break.
This issue is fixed by adding a ps_lock mutex around UART break on/off as
well as around ps_state read/write.
btnxpuart_tx_wakeup() will now read updated ps_state value. If ps_state is
PS_STATE_SLEEP, it will first schedule psdata->work, and then it will
reschedule itself once UART break has been turned off and ps_state is
PS_STATE_AWAKE.
Tested above script for 50,000 iterations and TX timeout error was not
observed anymore. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: check changes_pkt_data property for extension programs
When processing calls to global sub-programs, verifier decides whether
to invalidate all packet pointers in current state depending on the
changes_pkt_data property of the global sub-program.
Because of this, an extension program replacing a global sub-program
must be compatible with changes_pkt_data property of the sub-program
being replaced.
This commit:
- adds changes_pkt_data flag to struct bpf_prog_aux:
- this flag is set in check_cfg() for main sub-program;
- in jit_subprogs() for other sub-programs;
- modifies bpf_check_attach_btf_id() to check changes_pkt_data flag;
- moves call to check_attach_btf_id() after the call to check_cfg(),
because it needs changes_pkt_data flag to be set:
bpf_check:
... ...
- check_attach_btf_id resolve_pseudo_ldimm64
resolve_pseudo_ldimm64 --> bpf_prog_is_offloaded
bpf_prog_is_offloaded check_cfg
check_cfg + check_attach_btf_id
... ...
The following fields are set by check_attach_btf_id():
- env->ops
- prog->aux->attach_btf_trace
- prog->aux->attach_func_name
- prog->aux->attach_func_proto
- prog->aux->dst_trampoline
- prog->aux->mod
- prog->aux->saved_dst_attach_type
- prog->aux->saved_dst_prog_type
- prog->expected_attach_type
Neither of these fields are used by resolve_pseudo_ldimm64() or
bpf_prog_offload_verifier_prep() (for netronome and netdevsim
drivers), so the reordering is safe. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: track changes_pkt_data property for global functions
When processing calls to certain helpers, verifier invalidates all
packet pointers in a current state. For example, consider the
following program:
__attribute__((__noinline__))
long skb_pull_data(struct __sk_buff *sk, __u32 len)
{
return bpf_skb_pull_data(sk, len);
}
SEC("tc")
int test_invalidate_checks(struct __sk_buff *sk)
{
int *p = (void *)(long)sk->data;
if ((void *)(p + 1) > (void *)(long)sk->data_end) return TCX_DROP;
skb_pull_data(sk, 0);
*p = 42;
return TCX_PASS;
}
After a call to bpf_skb_pull_data() the pointer 'p' can't be used
safely. See function filter.c:bpf_helper_changes_pkt_data() for a list
of such helpers.
At the moment verifier invalidates packet pointers when processing
helper function calls, and does not traverse global sub-programs when
processing calls to global sub-programs. This means that calls to
helpers done from global sub-programs do not invalidate pointers in
the caller state. E.g. the program above is unsafe, but is not
rejected by verifier.
This commit fixes the omission by computing field
bpf_subprog_info->changes_pkt_data for each sub-program before main
verification pass.
changes_pkt_data should be set if:
- subprogram calls helper for which bpf_helper_changes_pkt_data
returns true;
- subprogram calls a global function,
for which bpf_subprog_info->changes_pkt_data should be set.
The verifier.c:check_cfg() pass is modified to compute this
information. The commit relies on depth first instruction traversal
done by check_cfg() and absence of recursive function calls:
- check_cfg() would eventually visit every call to subprogram S in a
state when S is fully explored;
- when S is fully explored:
- every direct helper call within S is explored
(and thus changes_pkt_data is set if needed);
- every call to subprogram S1 called by S was visited with S1 fully
explored (and thus S inherits changes_pkt_data from S1).
The downside of such approach is that dead code elimination is not
taken into account: if a helper call inside global function is dead
because of current configuration, verifier would conservatively assume
that the call occurs for the purpose of the changes_pkt_data
computation. |
| In the Linux kernel, the following vulnerability has been resolved:
media: uvcvideo: Fix crash during unbind if gpio unit is in use
We used the wrong device for the device managed functions. We used the
usb device, when we should be using the interface device.
If we unbind the driver from the usb interface, the cleanup functions
are never called. In our case, the IRQ is never disabled.
If an IRQ is triggered, it will try to access memory sections that are
already free, causing an OOPS.
We cannot use the function devm_request_threaded_irq here. The devm_*
clean functions may be called after the main structure is released by
uvc_delete.
Luckily this bug has small impact, as it is only affected by devices
with gpio units and the user has to unbind the device, a disconnect will
not trigger this error. |
| In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Fix handling of received connection abort
Fix the handling of a connection abort that we've received. Though the
abort is at the connection level, it needs propagating to the calls on that
connection. Whilst the propagation bit is performed, the calls aren't then
woken up to go and process their termination, and as no further input is
forthcoming, they just hang.
Also add some tracing for the logging of connection aborts. |
