linux/include
Emil Tsalapatis f85f5917aa
bpf: Prevent variable arena/non-arena register contents
The verifier marks ALU instructions that include at least
one arena operand with needs_zext: These instructions are
fixed up after verification to be ALU32 instructions to
ensure that the result is a valid offset into an arena.
However, different code paths may provide two non-arena
64-bit arguments to the same instruction. The result of
the operation in that code path is wrong, since it is
now unexpectedly truncated to 32 bits and zero-extended.

Add logic to the verifier to ensure every instruction either
always has at least one PTR_TO_ARENA argument, or never does.
Since needs_zext already tracks the first scenario, add a
prevent_zext field in bpf_insn_aux to track the latter.
Reject instructions that use arena arguments and have prevent_zext
set, or do not have arena arguments and have needs_zext set.

Fixes: 6082b6c328 ("bpf: Recognize addr_space_cast instruction in the verifier.")
Reported-by: Nicholas Carlini <nicholas@carlini.com>
Suggested-by: Nicholas Carlini <nicholas@carlini.com>
Signed-off-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://patch.msgid.link/20260922172028.6269-8-emil@etsalapatis.com
2026-09-22 19:34:04 +00:00
..
acpi ACPI: bus: Drop two fields from struct acpi_device_pnp 2026-09-01 21:45:50 +02:00
asm-generic kho: make boot time huge page allocation work nicely with KHO 2026-08-23 09:17:38 -07:00
clocksource hyperv-next for v7.3-rc1 2026-08-26 16:47:40 -07:00
crypto This update includes the following changes: 2026-08-19 17:25:42 -07:00
cxl
drm Merge drm/drm-fixes into drm-misc-fixes 2026-09-01 09:38:51 +02:00
dt-bindings sound fixes for 7.3-rc1 2026-08-28 10:01:02 -07:00
hyperv
keys tpm: Initial step to reorganize TPM public headers 2026-08-25 18:13:35 +03:00
kunit gpio updates for v7.3-rc1 2026-08-19 09:10:07 -07:00
kvm KVM/arm64 changes for 7.3 2026-08-24 12:42:07 -04:00
linux bpf: Prevent variable arena/non-arena register contents 2026-09-22 19:34:04 +00:00
math-emu
media
memory
misc
net ipv6: mcast: use copy-on-write RCU updates in ip6_mc_source() 2026-08-31 17:54:45 -07:00
pcmcia
ras
rdma
rv mm.git review status for linus..mm-stable 2026-08-27 09:17:06 -07:00
scsi SCSI updates for 7.3 2026-08-29 11:55:36 -07:00
soc Mostly the usual clk driver updates and new SoC additions plus non-critical 2026-08-26 11:14:30 -07:00
sound ALSA: rawmidi: Another workaround for false-positive mutex lockdep warning 2026-08-25 15:55:37 +02:00
target
trace Including fixes from bluetooth. 2026-09-03 10:18:12 -07:00
uapi integrity-v7.3-rc2 2026-09-04 19:36:11 -07:00
ufs
vdso
video fbdev: maxine: fix 64-bit build error 2026-08-20 23:45:07 +02:00
xen
Kbuild