From 33a154a96e71a34a1bcca9f40da343dbbf7b38b4 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Thu, 1 Oct 2026 14:52:55 +0000 Subject: selftests/bpf: Test packet range of pointers sharing an id Add tests where two packet pointers share an id and tightening one pointer's umax from its var_off would put it less than their constant distance from the other's umax: with an index & 0x38 capped at 50, the base pointer keeps umax 50, so the pointer 8 bytes further on must keep umax 58, even though its known bits allow at most 56. These refused a valid program or accepted an out-of-bounds access before the fix: - check the advanced copy, load through the base: valid, was refused; - check the base, load the byte at base + 1 through a copy advanced by 8: was accepted; - check base + 4, load 4 bytes at base + 2 through base + 8: reads two bytes past the checked range, was accepted; - the same as the second with data_meta pointers checked against data: was accepted. These pass with and without the fix and cover nearby paths: - subtract an unknown scalar from a checked pointer and load below it (the range is kept across a new id); - reach a load through two paths whose checks cover 8 and 7 bytes after the loaded pointer; the second path must not be pruned by the first; - spill a copy of a pointer, check the pointer, fill the copy and load one byte past the checked range: the load is refused, and the copy has the range of the check. Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20261001145255.855630-2-alexei.starovoitov@gmail.com Signed-off-by: Kumar Kartikeya Dwivedi --- include/uapi/asm-generic/msgbuf.h | 49 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 include/uapi/asm-generic/msgbuf.h (limited to 'include/uapi/asm-generic/msgbuf.h') diff --git a/include/uapi/asm-generic/msgbuf.h b/include/uapi/asm-generic/msgbuf.h new file mode 100644 index 000000000..6504d7b74 --- /dev/null +++ b/include/uapi/asm-generic/msgbuf.h @@ -0,0 +1,49 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +#ifndef __ASM_GENERIC_MSGBUF_H +#define __ASM_GENERIC_MSGBUF_H + +#include +#include + +/* + * generic msqid64_ds structure. + * + * Note extra padding because this structure is passed back and forth + * between kernel and user space. + * + * msqid64_ds was originally meant to be architecture specific, but + * everyone just ended up making identical copies without specific + * optimizations, so we may just as well all use the same one. + * + * 64 bit architectures use a 64-bit long time field here, while + * 32 bit architectures have a pair of unsigned long values. + * On big-endian systems, the lower half is in the wrong place. + * + * Pad space is left for: + * - 2 miscellaneous 32-bit values + */ + +struct msqid64_ds { + struct ipc64_perm msg_perm; +#if __BITS_PER_LONG == 64 + long msg_stime; /* last msgsnd time */ + long msg_rtime; /* last msgrcv time */ + long msg_ctime; /* last change time */ +#else + unsigned long msg_stime; /* last msgsnd time */ + unsigned long msg_stime_high; + unsigned long msg_rtime; /* last msgrcv time */ + unsigned long msg_rtime_high; + unsigned long msg_ctime; /* last change time */ + unsigned long msg_ctime_high; +#endif + unsigned long msg_cbytes; /* current number of bytes on queue */ + unsigned long msg_qnum; /* number of messages in queue */ + unsigned long msg_qbytes; /* max number of bytes on queue */ + __kernel_pid_t msg_lspid; /* pid of last msgsnd */ + __kernel_pid_t msg_lrpid; /* last receive pid */ + unsigned long __unused4; + unsigned long __unused5; +}; + +#endif /* __ASM_GENERIC_MSGBUF_H */ -- cgit v1.3.1