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Nathan Lynch 262e942ff5 powerpc/pseries: Enforce hcall result buffer validity and size
[ Upstream commit ff2e185cf7 ]

plpar_hcall(), plpar_hcall9(), and related functions expect callers to
provide valid result buffers of certain minimum size. Currently this
is communicated only through comments in the code and the compiler has
no idea.

For example, if I write a bug like this:

  long retbuf[PLPAR_HCALL_BUFSIZE]; // should be PLPAR_HCALL9_BUFSIZE
  plpar_hcall9(H_ALLOCATE_VAS_WINDOW, retbuf, ...);

This compiles with no diagnostics emitted, but likely results in stack
corruption at runtime when plpar_hcall9() stores results past the end
of the array. (To be clear this is a contrived example and I have not
found a real instance yet.)

To make this class of error less likely, we can use explicitly-sized
array parameters instead of pointers in the declarations for the hcall
APIs. When compiled with -Warray-bounds[1], the code above now
provokes a diagnostic like this:

error: array argument is too small;
is of size 32, callee requires at least 72 [-Werror,-Warray-bounds]
   60 |                 plpar_hcall9(H_ALLOCATE_VAS_WINDOW, retbuf,
      |                 ^                                   ~~~~~~

[1] Enabled for LLVM builds but not GCC for now. See commit
    0da6e5fd6c ("gcc: disable '-Warray-bounds' for gcc-13 too") and
    related changes.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240408-pseries-hvcall-retbuf-v1-1-ebc73d7253cf@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-05 09:14:27 +02:00
arch powerpc/pseries: Enforce hcall result buffer validity and size 2024-07-05 09:14:27 +02:00
block block/ioctl: prefer different overflow check 2024-07-05 09:14:25 +02:00
certs
crypto crypto: ecrdsa - Fix module auto-load on add_key 2024-06-16 13:39:58 +02:00
Documentation net: ena: Add dynamic recycling mechanism for rx buffers 2024-06-16 13:39:52 +02:00
drivers drm/lima: mask irqs in timeout path before hard reset 2024-07-05 09:14:27 +02:00
fs nilfs2: fix potential kernel bug due to lack of writeback flag waiting 2024-07-05 09:14:22 +02:00
include hugetlb_encode.h: fix undefined behaviour (34 << 26) 2024-07-05 09:14:23 +02:00
init init/main.c: Fix potential static_command_line memory overflow 2024-04-27 17:05:28 +02:00
io_uring io_uring: fail NOP if non-zero op flags is passed in 2024-06-16 13:39:53 +02:00
ipc
kernel rcutorture: Fix invalid context warning when enable srcu barrier testing 2024-07-05 09:14:25 +02:00
lib mm/slub, kunit: Use inverted data to corrupt kmem cache 2024-06-16 13:39:16 +02:00
LICENSES
mm mm/huge_memory: don't unpoison huge_zero_folio 2024-07-05 09:14:22 +02:00
net netpoll: Fix race condition in netpoll_owner_active 2024-07-05 09:14:26 +02:00
samples samples/hw_breakpoint: fix building without module unloading 2023-09-23 11:10:01 +02:00
scripts scripts/gdb: fix SB_* constants parsing 2024-06-16 13:39:54 +02:00
security KEYS: trusted: Do not use WARN when encode fails 2024-05-25 16:20:18 +02:00
sound ALSA: timer: Set lower bound of start tick time 2024-06-16 13:39:52 +02:00
tools kselftest: arm64: Add a null pointer check 2024-07-05 09:14:26 +02:00
usr
virt KVM: Always flush async #PF workqueue when vCPU is being destroyed 2024-04-10 16:18:34 +02:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS trace: Relocate event helper files 2024-04-10 16:19:24 +02:00
Makefile kbuild: Remove support for Clang's ThinLTO caching 2024-07-05 09:14:23 +02:00
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