mirror-linux/include
Fernando Fernandez Mancera 18014147d3 netfilter: nf_tables: fix dst corruption in same register operation
For lshift and rshift, the shift operations are performed in a loop over
32-bit words. The loop calculates the shifted value and write it to dst,
and then immediately reads from src to calculate the carry for the next
iteration. Because src and dst could point to the same memory location,
the carry is incorrectly calculated using the newly modified dst value
instead of the original src value.

Adding a temporary local variable to cache the original value before
writing to dst and using it for the carry calculation solves the
problem. In addition, partial overlap is rejected from control plane for
all kind of operations including byteorder. This was tested with the
following bytecode:

table test_table ip flags 0 use 1 handle 1
ip test_table test_chain use 3 type filter hook input prio 0 policy accept packets 0 bytes 0 flags 1
ip test_table test_chain 2
  [ immediate reg 1 0x44332211 0x88776655 ]
  [ bitwise reg 1 = ( reg 1 << 0x08000000 ) ]
  [ cmp eq reg 1 0x66443322 0x00887766 ]
  [ counter pkts 0 bytes 0 ]
ip test_table test_chain 4 3
  [ immediate reg 1 0x44332211 0x88776655 ]
  [ bitwise reg 1 = ( reg 1 << 0x08000000 ) ]
  [ cmp eq reg 1 0x55443322 0x00887766 ]
  [ counter pkts 21794 bytes 1917798 ]

Fixes: 567d746b55 ("netfilter: bitwise: add support for shifts.")
Acked-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
2026-05-22 12:28:46 +02:00
..
acpi Merge branches 'acpi-apei', 'acpi-bus', 'acpi-cppc' and 'acpi-video' 2026-04-30 21:07:06 +02:00
asm-generic ring-buffer: Flush and stop persistent ring buffer on panic 2026-05-21 08:20:58 -04:00
clocksource
crypto crypto/krb5, rxrpc: Fix lack of pre-decrypt/pre-verify length checks 2026-05-20 16:36:45 -07:00
cxl
drm Short summary of fixes pull: 2026-05-16 07:56:32 +10:00
dt-bindings We've finally gotten rid of the struct clk_ops::round_rate() code after months 2026-04-21 08:33:26 -07:00
hyperv x86/hyperv: Skip LP/VP creation on kexec 2026-04-22 06:23:25 +00:00
keys
kunit
kvm
linux netfilter: nf_conntrack_gre: fix gre keymap list corruption 2026-05-22 12:28:46 +02:00
math-emu
media
memory
misc
net netfilter: nf_tables: fix dst corruption in same register operation 2026-05-22 12:28:46 +02:00
pcmcia
ras
rdma
rv
scsi
soc
sound ASoC: Fixes for v7.1 2026-04-23 09:34:28 +02:00
target
trace Including fixes from Bluetooth, wireless and netfilter. 2026-05-21 14:39:12 -07:00
uapi Miscellaneous scheduler fixes: 2026-05-08 19:42:10 -07:00
ufs scsi: ufs: core: Fix bRefClkFreq write failure in HS-LSS mode 2026-04-21 20:58:06 -04:00
vdso
video fbdev: udlfb: add vm_ops to dlfb_ops_mmap to prevent use-after-free 2026-05-04 10:35:55 +02:00
xen xen/arm: Replace __ASSEMBLY__ with __ASSEMBLER__ in interface.h 2026-05-12 17:31:38 +02:00
Kbuild