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Filename Latest commit message Latest commit date
Jakub Sitnicki f7990498b0 bpf, sockmap: Prevent lock inversion deadlock in map delete elem
commit ff91059932401894e6c86341915615c5eb0eca48 upstream.

syzkaller started using corpuses where a BPF tracing program deletes
elements from a sockmap/sockhash map. Because BPF tracing programs can be
invoked from any interrupt context, locks taken during a map_delete_elem
operation must be hardirq-safe. Otherwise a deadlock due to lock inversion
is possible, as reported by lockdep:

       CPU0                    CPU1
       ----                    ----
  lock(&htab->buckets[i].lock);
                               local_irq_disable();
                               lock(&host->lock);
                               lock(&htab->buckets[i].lock);
  <Interrupt>
    lock(&host->lock);

Locks in sockmap are hardirq-unsafe by design. We expects elements to be
deleted from sockmap/sockhash only in task (normal) context with interrupts
enabled, or in softirq context.

Detect when map_delete_elem operation is invoked from a context which is
_not_ hardirq-unsafe, that is interrupts are disabled, and bail out with an
error.

Note that map updates are not affected by this issue. BPF verifier does not
allow updating sockmap/sockhash from a BPF tracing program today.

Fixes: 604326b41a ("bpf, sockmap: convert to generic sk_msg interface")
Reported-by: xingwei lee <xrivendell7@gmail.com>
Reported-by: yue sun <samsun1006219@gmail.com>
Reported-by: syzbot+bc922f476bd65abbd466@syzkaller.appspotmail.com
Reported-by: syzbot+d4066896495db380182e@syzkaller.appspotmail.com
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: syzbot+d4066896495db380182e@syzkaller.appspotmail.com
Acked-by: John Fastabend <john.fastabend@gmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=d4066896495db380182e
Closes: https://syzkaller.appspot.com/bug?extid=bc922f476bd65abbd466
Link: https://lore.kernel.org/bpf/20240402104621.1050319-1-jakub@cloudflare.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-13 12:51:34 +02:00
arch Revert "x86/mm/ident_map: Use gbpages only where full GB page should be mapped." 2024-04-13 12:51:34 +02:00
block
certs
crypto
Documentation x86/cpu: Enable STIBP on AMD if Automatic IBRS is enabled 2024-04-13 12:51:32 +02:00
drivers vfio/platform: Create persistent IRQ handlers 2024-04-13 12:51:34 +02:00
fs exec: Fix NOMMU linux_binprm::exec in transfer_args_to_stack() 2024-04-13 12:51:31 +02:00
include mm, vmscan: prevent infinite loop for costly GFP_NOIO | __GFP_RETRY_MAYFAIL allocations 2024-04-13 12:51:34 +02:00
init
ipc
kernel bounds: support non-power-of-two CONFIG_NR_CPUS 2024-04-13 12:51:31 +02:00
lib
LICENSES
mm mm, vmscan: prevent infinite loop for costly GFP_NOIO | __GFP_RETRY_MAYFAIL allocations 2024-04-13 12:51:34 +02:00
net bpf, sockmap: Prevent lock inversion deadlock in map delete elem 2024-04-13 12:51:34 +02:00
samples media: rename VFL_TYPE_GRABBER to _VIDEO 2024-03-26 18:22:22 -04:00
scripts kbuild: Move -Wenum-{compare-conditional,enum-conversion} into W=1 2024-04-13 12:51:26 +02:00
security smack: Handle SMACK64TRANSMUTE in smack_inode_setsecurity() 2024-04-13 12:51:22 +02:00
sound ALSA: sh: aica: reorder cleanup operations to avoid UAF bugs 2024-04-13 12:51:32 +02:00
tools objtool: Add support for intra-function calls 2024-04-13 12:51:29 +02:00
usr
virt KVM: Always flush async #PF workqueue when vCPU is being destroyed 2024-04-13 12:51:22 +02:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS
Makefile Linux 5.4.273 2024-03-26 18:23:12 -04:00
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.