From 836b2fe544a5e9b5ce116622cb36fba33838c6fd Mon Sep 17 00:00:00 2001 From: Eduard Zingerman Date: Fri, 4 Sep 2026 01:33:23 -0700 Subject: selftests/bpf: Check that JMP32 pointer vs zero jumps are not predicted Add jmp32_ptr_vs_zero_jne: the fall-through of the 32-bit compare, which the verifier used to skip, contains an out of bounds map value access, hence w/o the previous patch the program is accepted. See previous patch for detailed description. Reported-by: Nicholas Carlini Suggested-by: Nicholas Carlini Signed-off-by: Eduard Zingerman Link: https://lore.kernel.org/bpf/20260904083325.2083493-6-eddyz87@gmail.com Signed-off-by: Kumar Kartikeya Dwivedi --- samples/watchdog/.gitignore | 2 ++ samples/watchdog/Makefile | 2 ++ samples/watchdog/watchdog-simple.c | 25 +++++++++++++++++++++++++ 3 files changed, 29 insertions(+) create mode 100644 samples/watchdog/.gitignore create mode 100644 samples/watchdog/Makefile create mode 100644 samples/watchdog/watchdog-simple.c (limited to 'samples/watchdog') diff --git a/samples/watchdog/.gitignore b/samples/watchdog/.gitignore new file mode 100644 index 000000000..a70a0150e --- /dev/null +++ b/samples/watchdog/.gitignore @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +/watchdog-simple diff --git a/samples/watchdog/Makefile b/samples/watchdog/Makefile new file mode 100644 index 000000000..ab39d23dc --- /dev/null +++ b/samples/watchdog/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0 +userprogs-always-y += watchdog-simple diff --git a/samples/watchdog/watchdog-simple.c b/samples/watchdog/watchdog-simple.c new file mode 100644 index 000000000..9ce66d2ca --- /dev/null +++ b/samples/watchdog/watchdog-simple.c @@ -0,0 +1,25 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include + +int main(void) +{ + int fd = open("/dev/watchdog", O_WRONLY); + int ret = 0; + if (fd == -1) { + perror("watchdog"); + exit(EXIT_FAILURE); + } + while (1) { + ret = write(fd, "\0", 1); + if (ret != 1) { + ret = -1; + break; + } + sleep(10); + } + close(fd); + return ret; +} -- cgit v1.3.1