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Filename Latest commit message Latest commit date
Toke Høiland-Jørgensen 1f5e352b90 bpf: Fix DEVMAP_HASH overflow check on 32-bit arches
commit 281d464a34f540de166cee74b723e97ac2515ec3 upstream.

The devmap code allocates a number hash buckets equal to the next power
of two of the max_entries value provided when creating the map. When
rounding up to the next power of two, the 32-bit variable storing the
number of buckets can overflow, and the code checks for overflow by
checking if the truncated 32-bit value is equal to 0. However, on 32-bit
arches the rounding up itself can overflow mid-way through, because it
ends up doing a left-shift of 32 bits on an unsigned long value. If the
size of an unsigned long is four bytes, this is undefined behaviour, so
there is no guarantee that we'll end up with a nice and tidy 0-value at
the end.

Syzbot managed to turn this into a crash on arm32 by creating a
DEVMAP_HASH with max_entries > 0x80000000 and then trying to update it.
Fix this by moving the overflow check to before the rounding up
operation.

Fixes: 6f9d451ab1 ("xdp: Add devmap_hash map type for looking up devices by hashed index")
Link: https://lore.kernel.org/r/000000000000ed666a0611af6818@google.com
Reported-and-tested-by: syzbot+8cd36f6b65f3cafd400a@syzkaller.appspotmail.com
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Message-ID: <20240307120340.99577-2-toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-08 16:20:26 +01:00
arch x86/hyperv: Set X86_FEATURE_TSC_KNOWN_FREQ when Hyper-V provides frequency 2024-11-08 16:20:26 +01:00
block block: initialize integrity buffer to zero before writing it to media 2024-09-12 11:03:50 +02:00
certs
crypto crypto: ecrdsa - Fix module auto-load on add_key 2024-06-16 13:28:51 +02:00
Documentation overflow: Implement size_t saturating arithmetic helpers 2024-09-04 13:14:51 +02:00
drivers gpio: prevent potential speculation leaks in gpio_device_get_desc() 2024-11-08 16:20:26 +01:00
fs ocfs2: strict bound check before memcmp in ocfs2_xattr_find_entry() 2024-11-08 16:20:26 +01:00
include inet: inet_defrag: prevent sk release while still in use 2024-11-08 16:20:26 +01:00
init init: open /initrd.image with O_LARGEFILE 2024-04-13 12:51:36 +02:00
ipc ipc: replace costly bailout check in sysvipc_find_ipc() 2024-09-04 13:15:02 +02:00
kernel bpf: Fix DEVMAP_HASH overflow check on 32-bit arches 2024-11-08 16:20:26 +01:00
lib lib/generic-radix-tree.c: Fix rare race in __genradix_ptr_alloc() 2024-09-12 11:03:55 +02:00
LICENSES
mm memcg_write_event_control(): fix a user-triggerable oops 2024-09-04 13:14:50 +02:00
net inet: inet_defrag: prevent sk release while still in use 2024-11-08 16:20:26 +01:00
samples media: rename VFL_TYPE_GRABBER to _VIDEO 2024-03-26 18:22:22 -04:00
scripts scripts: kconfig: merge_config: config files: add a trailing newline 2024-11-08 16:20:24 +01:00
security smack: unix sockets: fix accept()ed socket label 2024-09-12 11:03:52 +02:00
sound ASoC: tda7419: fix module autoloading 2024-11-08 16:20:25 +01:00
tools selftests: breakpoints: Fix a typo of function name 2024-11-08 16:20:25 +01:00
usr
virt KVM: async_pf: Cleanup kvm_setup_async_pf() 2024-05-02 16:18:32 +02:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS
Makefile Linux 5.4.284 2024-09-12 11:03:57 +02:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.