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 --- drivers/s390/char/ctrlchar.c | 80 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+) create mode 100644 drivers/s390/char/ctrlchar.c (limited to 'drivers/s390/char/ctrlchar.c') diff --git a/drivers/s390/char/ctrlchar.c b/drivers/s390/char/ctrlchar.c new file mode 100644 index 000000000..6f2b64040 --- /dev/null +++ b/drivers/s390/char/ctrlchar.c @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Unified handling of special chars. + * + * Copyright IBM Corp. 2001 + * Author(s): Fritz Elfert + * + */ + +#include +#include +#include +#include + +#include "ctrlchar.h" + +#ifdef CONFIG_MAGIC_SYSRQ +static struct sysrq_work ctrlchar_sysrq; + +static void +ctrlchar_handle_sysrq(struct work_struct *work) +{ + struct sysrq_work *sysrq = container_of(work, struct sysrq_work, work); + + handle_sysrq(sysrq->key); +} + +void schedule_sysrq_work(struct sysrq_work *sw) +{ + INIT_WORK(&sw->work, ctrlchar_handle_sysrq); + schedule_work(&sw->work); +} +#endif + + +/** + * ctrlchar_handle - check for special chars at start of input + * + * @buf: console input buffer + * @len: length of valid data in buffer + * @tty: the tty struct for this console + * + * Return: CTRLCHAR_NONE, if nothing matched, + * CTRLCHAR_SYSRQ, if sysrq was encountered + * otherwise char to be inserted logically or'ed + * with CTRLCHAR_CTRL + */ +unsigned int +ctrlchar_handle(const unsigned char *buf, int len, struct tty_struct *tty) +{ + if ((len < 2) || (len > 3)) + return CTRLCHAR_NONE; + + /* hat is 0xb1 in codepage 037 (US etc.) and thus */ + /* converted to 0x5e in ascii ('^') */ + if ((buf[0] != '^') && (buf[0] != '\252')) + return CTRLCHAR_NONE; + +#ifdef CONFIG_MAGIC_SYSRQ + /* racy */ + if (len == 3 && buf[1] == '-') { + ctrlchar_sysrq.key = buf[2]; + schedule_sysrq_work(&ctrlchar_sysrq); + return CTRLCHAR_SYSRQ; + } +#endif + + if (len != 2) + return CTRLCHAR_NONE; + + switch (tolower(buf[1])) { + case 'c': + return INTR_CHAR(tty) | CTRLCHAR_CTRL; + case 'd': + return EOF_CHAR(tty) | CTRLCHAR_CTRL; + case 'z': + return SUSP_CHAR(tty) | CTRLCHAR_CTRL; + } + return CTRLCHAR_NONE; +} -- cgit v1.3.1