kvm: avoid speculation-based attacks from out-of-range memslot accesses
In the Linux kernel, the following vulnerability has been resolved:
kvm: avoid speculation-based attacks from out-of-range memslot accesses
KVM's mechanism for accessing guest memory translates a guest physical
address (gpa) to a host virtual address using the right-shifted gpa
(also known as gfn) and a struct kvm_memory_slot. The translation is
performed in __gfn_to_hva_memslot using the following formula:
hva = slot->userspace_addr + (gfn - slot->base_gfn) * PAGE_SIZE
It is expected that gfn falls within the boundaries of the guest's
physical memory. However, a guest can access invalid physical addresses
in such a way that the g
ftrace: Do not blindly read the ip address in ftrace_bug()
In the Linux kernel, the following vulnerability has been resolved:
ftrace: Do not blindly read the ip address in ftrace_bug()
It was reported that a bug on arm64 caused a bad ip address to be used for
updating into a nop in ftrace_init(), but the error path (rightfully)
returned -EINVAL and not -EFAULT, as the bug caused more than one error to
occur. But because -EINVAL was returned, the ftrace_bug() tried to report
what was at the location of the ip address, and read it directly. This
caused the machine to panic, as the ip was not pointing to a valid memory
address.
Instead, read the ip address with copy_from_kernel_nofault() to safely
a
tracing: Correct the length check which causes memory corruption
In the Linux kernel, the following vulnerability has been resolved:
tracing: Correct the length check which causes memory corruption
We've suffered from severe kernel crashes due to memory corruption on
our production environment, like,
Call Trace:
[1640542.554277] general protection fault: 0000 [#1] SMP PTI
[1640542.554856] CPU: 17 PID: 26996 Comm: python Kdump: loaded Tainted:G
[1640542.556629] RIP: 0010:kmem_cache_alloc+0x90/0x190
[1640542.559074] RSP: 0018:ffffb16faa597df8 EFLAGS: 00010286
[1640542.559587] RAX: 0000000000000000 RBX: 0000000000400200 RCX:
0000000006e931bf
[1640542.560323] RDX: 0000000006e931be RSI: 0000000000400200 RDI:
usb: fix various gadgets null ptr deref on 10gbps cabling.
In the Linux kernel, the following vulnerability has been resolved:
usb: fix various gadgets null ptr deref on 10gbps cabling.
This avoids a null pointer dereference in
f_{ecm,eem,hid,loopback,printer,rndis,serial,sourcesink,subset,tcm}
by simply reusing the 5gbps config for 10gbps.
In the Linux kernel, the following vulnerability has been resolved:
usb: dwc3: ep0: fix NULL pointer exception
There is no validation of the index from dwc3_wIndex_to_dep() and we might
be referring a non-existing ep and trigger a NULL pointer exception. In
certain configurations we might use fewer eps and the index might wrongly
indicate a larger ep index than existing.
By adding this validation from the patch we can actually report a wrong
index back to the caller.
In our usecase we are using a composite device on an older kernel, but
upstream might use this fix also. Unfortunately, I cannot describe the
hardware for others to reproduce
In the Linux kernel, the following vulnerability has been resolved:
usb: fix various gadget panics on 10gbps cabling
usb_assign_descriptors() is called with 5 parameters,
the last 4 of which are the usb_descriptor_header for:
full-speed (USB1.1 - 12Mbps [including USB1.0 low-speed @ 1.5Mbps),
high-speed (USB2.0 - 480Mbps),
super-speed (USB3.0 - 5Gbps),
super-speed-plus (USB3.1 - 10Gbps).
The differences between full/high/super-speed descriptors are usually
substantial (due to changes in the maximum usb block size from 64 to 512
to 1024 bytes and other differences in the specs), while the difference
between 5 and 10Gbps descriptors
RDMA/ipoib: Fix warning caused by destroying non-initial netns
In the Linux kernel, the following vulnerability has been resolved:
RDMA/ipoib: Fix warning caused by destroying non-initial netns
After the commit 5ce2dced8e95 ("RDMA/ipoib: Set rtnl_link_ops for ipoib
interfaces"), if the IPoIB device is moved to non-initial netns,
destroying that netns lets the device vanish instead of moving it back to
the initial netns, This is happening because default_device_exit() skips
the interfaces due to having rtnl_link_ops set.
Steps to reporoduce:
ip netns add foo
ip link set mlx5_ib0 netns foo
ip netns delete foo
WARNING: CPU: 1 PID: 704 at net/core/dev.c:11435 netdev_exit+0x3f/0x50
Modules linked in
KVM: x86: Ensure liveliness of nested VM-Enter fail tracepoint message
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Ensure liveliness of nested VM-Enter fail tracepoint message
Use the __string() machinery provided by the tracing subystem to make a
copy of the string literals consumed by the "nested VM-Enter failed"
tracepoint. A complete copy is necessary to ensure that the tracepoint
can't outlive the data/memory it consumes and deference stale memory.
Because the tracepoint itself is defined by kvm, if kvm-intel and/or
kvm-amd are built as modules, the memory holding the string literals
defined by the vendor modules will be freed when the module is unloaded,
whereas the tr
In the Linux kernel, the following vulnerability has been resolved:
IB/mlx5: Fix initializing CQ fragments buffer
The function init_cq_frag_buf() can be called to initialize the current CQ
fragments buffer cq->buf, or the temporary cq->resize_buf that is filled
during CQ resize operation.
However, the offending commit started to use function get_cqe() for
getting the CQEs, the issue with this change is that get_cqe() always
returns CQEs from cq->buf, which leads us to initialize the wrong buffer,
and in case of enlarging the CQ we try to access elements beyond the size
of the current cq->buf and eventually hit a kernel panic.
[exception
NFS: Fix a potential NULL dereference in nfs_get_client()
In the Linux kernel, the following vulnerability has been resolved:
NFS: Fix a potential NULL dereference in nfs_get_client()
None of the callers are expecting NULL returns from nfs_get_client() so
this code will lead to an Oops. It's better to return an error
pointer. I expect that this is dead code so hopefully no one is
affected.
In the Linux kernel, the following vulnerability has been resolved:
NFS: Fix use-after-free in nfs4_init_client()
KASAN reports a use-after-free when attempting to mount two different
exports through two different NICs that belong to the same server.
Olga was able to hit this with kernels starting somewhere between 5.7
and 5.10, but I traced the patch that introduced the clear_bit() call to
4.13. So something must have changed in the refcounting of the clp
pointer to make this call to nfs_put_client() the very last one.
scsi: core: Fix error handling of scsi_host_alloc()
In the Linux kernel, the following vulnerability has been resolved:
scsi: core: Fix error handling of scsi_host_alloc()
After device is initialized via device_initialize(), or its name is set via
dev_set_name(), the device has to be freed via put_device(). Otherwise
device name will be leaked because it is allocated dynamically in
dev_set_name().
Fix the leak by replacing kfree() with put_device(). Since
scsi_host_dev_release() properly handles IDA and kthread removal, remove
special-casing these from the error handling as well.
In the Linux kernel, the following vulnerability has been resolved:
net: ieee802154: fix null deref in parse dev addr
Fix a logic error that could result in a null deref if the user sets
the mode incorrectly for the given addr type.
mm/memory-failure: make sure wait for page writeback in memory_failure
In the Linux kernel, the following vulnerability has been resolved:
mm/memory-failure: make sure wait for page writeback in memory_failure
Our syzkaller trigger the "BUG_ON(!list_empty(&inode->i_wb_list))" in
clear_inode:
kernel BUG at fs/inode.c:519!
Internal error: Oops - BUG: 0 [#1] SMP
Modules linked in:
Process syz-executor.0 (pid: 249, stack limit = 0x00000000a12409d7)
CPU: 1 PID: 249 Comm: syz-executor.0 Not tainted 4.19.95
Hardware name: linux,dummy-virt (DT)
pstate: 80000005 (Nzcv daif -PAN -UAO)
pc : clear_inode+0x280/0x2a8
lr : clear_inode+0x280/0x2a8
Call trace:
clear_inode+0x280/0x2a8
ext4_clear_ino
kvm: LAPIC: Restore guard to prevent illegal APIC register access
In the Linux kernel, the following vulnerability has been resolved:
kvm: LAPIC: Restore guard to prevent illegal APIC register access
Per the SDM, "any access that touches bytes 4 through 15 of an APIC
register may cause undefined behavior and must not be executed."
Worse, such an access in kvm_lapic_reg_read can result in a leak of
kernel stack contents. Prior to commit 01402cf81051 ("kvm: LAPIC:
write down valid APIC registers"), such an access was explicitly
disallowed. Restore the guard that was removed in that commit.
gfs2: Fix use-after-free in gfs2_glock_shrink_scan
In the Linux kernel, the following vulnerability has been resolved:
gfs2: Fix use-after-free in gfs2_glock_shrink_scan
The GLF_LRU flag is checked under lru_lock in gfs2_glock_remove_from_lru() to
remove the glock from the lru list in __gfs2_glock_put().
On the shrink scan path, the same flag is cleared under lru_lock but because
of cond_resched_lock(&lru_lock) in gfs2_dispose_glock_lru(), progress on the
put side can be made without deleting the glock from the lru list.
Keep GLF_LRU across the race window opened by cond_resched_lock(&lru_lock) to
ensure correct behavior on both sides - clear GLF_LRU after list_del under
lru_lock.
In the Linux kernel, the following vulnerability has been resolved:
batman-adv: Avoid WARN_ON timing related checks
The soft/batadv interface for a queued OGM can be changed during the time
the OGM was queued for transmission and when the OGM is actually
transmitted by the worker.
But WARN_ON must be used to denote kernel bugs and not to print simple
warnings. A warning can simply be printed using pr_warn.
In the Linux kernel, the following vulnerability has been resolved:
net: rds: fix memory leak in rds_recvmsg
Syzbot reported memory leak in rds. The problem
was in unputted refcount in case of error.
int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
int msg_flags)
{
...
if (!rds_next_incoming(rs, &inc)) {
...
}
After this "if" inc refcount incremented and
if (rds_cmsg_recv(inc, msg, rs)) {
ret = -EFAULT;
goto out;
}
...
out:
return ret;
}
in case of rds_cmsg_recv() fail the refcount won't be
decremented. And it's easy to see from ftrace log, that
rds_inc_addref() don't have rds_inc_put() pair in
rds_rec
In the Linux kernel, the following vulnerability has been resolved:
udp: fix race between close() and udp_abort()
Kaustubh reported and diagnosed a panic in udp_lib_lookup().
The root cause is udp_abort() racing with close(). Both
racing functions acquire the socket lock, but udp{v6}_destroy_sock()
release it before performing destructive actions.
We can't easily extend the socket lock scope to avoid the race,
instead use the SOCK_DEAD flag to prevent udp_abort from doing
any action when the critical race happens.
Diagnosed-and-tested-by: Kaustubh Pandey <kapandey@codeaurora.org>