In the Linux kernel, the following vulnerability has been resolved:
bpf: Make sure internal and UAPI bpf_redirect flags don't overlap
The bpf_redirect_info is shared between the SKB and XDP redirect paths,
and the two paths use the same numeric flag values in the ri->flags
field (specifically, BPF_F_BROADCAST == BPF_F_NEXTHOP). This means that
if skb bpf_redirect_neigh() is used with a non-NULL params argument and,
subsequently, an XDP redirect is performed using the same
bpf_redirect_info struct, the XDP path will get confused and end up
crashing, which syzbot managed to trigger.
With the stack-allocated bpf_redirect_info, the structure is no longer
shared between the SKB and XDP paths, so the crash doesn't happen
anymore. However, different code paths using identically-numbered flag
values in the same struct field still seems like a bit of a mess, so
this patch cleans that up by moving the flag definitions together and
redefining the three flags in BPF_F_REDIRECT_INTERNAL to not overlap
with the flags used for XDP. It also adds a BUILD_BUG_ON() check to make
sure the overlap is not re-introduced by mistake.
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix overloading of MEM_UNINIT's meaning
Lonial reported an issue in the BPF verifier where check_mem_size_reg()
has the following code:
if (!tnum_is_const(reg->var_off))
/* For unprivileged variable accesses, disable raw
* mode so that the program is required to
* initialize all the memory that the helper could
* just partially fill up.
*/
meta = NULL;
This means that writes are not checked when the register containing the
size of the passed buffer has not a fixed size. Through this bug, a BPF
program can write to a map which is marked as read-only, for example,
.rodata global maps.
The problem is that MEM_UNINIT's initial meaning that "the passed buffer
to the BPF helper does not need to be initialized" which was added back
in commit 435faee1aae9 ("bpf, verifier: add ARG_PTR_TO_RAW_STACK type")
got overloaded over time with "the passed buffer is being written to".
The problem however is that checks such as the above which were added later
via 06c1c049721a ("bpf: allow helpers access to variable memory") set meta
to NULL in order force the user to always initialize the passed buffer to
the helper. Due to the current double meaning of MEM_UNINIT, this bypasses
verifier write checks to the memory (not boundary checks though) and only
assumes the latter memory is read instead.
Fix this by reverting MEM_UNINIT back to its original meaning, and having
MEM_WRITE as an annotation to BPF helpers in order to then trigger the
BPF verifier checks for writing to memory.
Some notes: check_arg_pair_ok() ensures that for ARG_CONST_SIZE{,_OR_ZERO}
we can access fn->arg_type[arg - 1] since it must contain a preceding
ARG_PTR_TO_MEM. For check_mem_reg() the meta argument can be removed
altogether since we do check both BPF_READ and BPF_WRITE. Same for the
equivalent check_kfunc_mem_size_reg().
In the Linux kernel, the following vulnerability has been resolved:
fsl/fman: Fix refcount handling of fman-related devices
In mac_probe() there are multiple calls to of_find_device_by_node(),
fman_bind() and fman_port_bind() which takes references to of_dev->dev.
Not all references taken by these calls are released later on error path
in mac_probe() and in mac_remove() which lead to reference leaks.
Add references release.
In the Linux kernel, the following vulnerability has been resolved:
be2net: fix potential memory leak in be_xmit()
The be_xmit() returns NETDEV_TX_OK without freeing skb
in case of be_xmit_enqueue() fails, add dev_kfree_skb_any() to fix it.
In the Linux kernel, the following vulnerability has been resolved:
net/sun3_82586: fix potential memory leak in sun3_82586_send_packet()
The sun3_82586_send_packet() returns NETDEV_TX_OK without freeing skb
in case of skb->len being too long, add dev_kfree_skb() to fix it.
In the Linux kernel, the following vulnerability has been resolved:
ACPI: PRM: Find EFI_MEMORY_RUNTIME block for PRM handler and context
PRMT needs to find the correct type of block to translate the PA-VA
mapping for EFI runtime services.
The issue arises because the PRMT is finding a block of type
EFI_CONVENTIONAL_MEMORY, which is not appropriate for runtime services
as described in Section 2.2.2 (Runtime Services) of the UEFI
Specification [1]. Since the PRM handler is a type of runtime service,
this causes an exception when the PRM handler is called.
[Firmware Bug]: Unable to handle paging request in EFI runtime service
WARNING: CPU: 22 PID: 4330 at drivers/firmware/efi/runtime-wrappers.c:341
__efi_queue_work+0x11c/0x170
Call trace:
Let PRMT find a block with EFI_MEMORY_RUNTIME for PRM handler and PRM
context.
If no suitable block is found, a warning message will be printed, but
the procedure continues to manage the next PRM handler.
However, if the PRM handler is actually called without proper allocation,
it would result in a failure during error handling.
By using the correct memory types for runtime services, ensure that the
PRM handler and the context are properly mapped in the virtual address
space during runtime, preventing the paging request error.
The issue is really that only memory that has been remapped for runtime
by the firmware can be used by the PRM handler, and so the region needs
to have the EFI_MEMORY_RUNTIME attribute.
[ rjw: Subject and changelog edits ]
In the Linux kernel, the following vulnerability has been resolved:
xfrm: validate new SA's prefixlen using SA family when sel.family is unset
This expands the validation introduced in commit 07bf7908950a ("xfrm:
Validate address prefix lengths in the xfrm selector.")
syzbot created an SA with
usersa.sel.family = AF_UNSPEC
usersa.sel.prefixlen_s = 128
usersa.family = AF_INET
Because of the AF_UNSPEC selector, verify_newsa_info doesn't put
limits on prefixlen_{s,d}. But then copy_from_user_state sets
x->sel.family to usersa.family (AF_INET). Do the same conversion in
verify_newsa_info before validating prefixlen_{s,d}, since that's how
prefixlen is going to be used later on.
In the Linux kernel, the following vulnerability has been resolved:
udf: fix uninit-value use in udf_get_fileshortad
Check for overflow when computing alen in udf_current_aext to mitigate
later uninit-value use in udf_get_fileshortad KMSAN bug[1].
After applying the patch reproducer did not trigger any issue[2].
[1] https://syzkaller.appspot.com/bug?extid=8901c4560b7ab5c2f9df
[2] https://syzkaller.appspot.com/x/log.txt?x=10242227980000
In the Linux kernel, the following vulnerability has been resolved:
octeon_ep: Add SKB allocation failures handling in __octep_oq_process_rx()
build_skb() returns NULL in case of a memory allocation failure so handle
it inside __octep_oq_process_rx() to avoid NULL pointer dereference.
__octep_oq_process_rx() is called during NAPI polling by the driver. If
skb allocation fails, keep on pulling packets out of the Rx DMA queue: we
shouldn't break the polling immediately and thus falsely indicate to the
octep_napi_poll() that the Rx pressure is going down. As there is no
associated skb in this case, don't process the packets and don't push them
up the network stack - they are skipped.
Helper function is implemented to unmmap/flush all the fragment buffers
used by the dropped packet. 'alloc_failures' counter is incremented to
mark the skb allocation error in driver statistics.
Found by Linux Verification Center (linuxtesting.org) with SVACE.