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/mtd/chips/chipreg.c | 102 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 102 insertions(+) create mode 100644 drivers/mtd/chips/chipreg.c (limited to 'drivers/mtd/chips/chipreg.c') diff --git a/drivers/mtd/chips/chipreg.c b/drivers/mtd/chips/chipreg.c new file mode 100644 index 000000000..a05e10368 --- /dev/null +++ b/drivers/mtd/chips/chipreg.c @@ -0,0 +1,102 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Registration for chip drivers + * + */ + +#include +#include +#include +#include +#include +#include +#include + +static DEFINE_SPINLOCK(chip_drvs_lock); +static LIST_HEAD(chip_drvs_list); + +void register_mtd_chip_driver(struct mtd_chip_driver *drv) +{ + spin_lock(&chip_drvs_lock); + list_add(&drv->list, &chip_drvs_list); + spin_unlock(&chip_drvs_lock); +} + +void unregister_mtd_chip_driver(struct mtd_chip_driver *drv) +{ + spin_lock(&chip_drvs_lock); + list_del(&drv->list); + spin_unlock(&chip_drvs_lock); +} + +static struct mtd_chip_driver *get_mtd_chip_driver (const char *name) +{ + struct mtd_chip_driver *ret = NULL, *this; + + spin_lock(&chip_drvs_lock); + + list_for_each_entry(this, &chip_drvs_list, list) { + if (!strcmp(this->name, name)) { + ret = this; + break; + } + } + if (ret && !try_module_get(ret->module)) + ret = NULL; + + spin_unlock(&chip_drvs_lock); + + return ret; +} + + /* Hide all the horrid details, like some silly person taking + get_module_symbol() away from us, from the caller. */ + +struct mtd_info *do_map_probe(const char *name, struct map_info *map) +{ + struct mtd_chip_driver *drv; + struct mtd_info *ret; + + drv = get_mtd_chip_driver(name); + + if (!drv && !request_module("%s", name)) + drv = get_mtd_chip_driver(name); + + if (!drv) + return NULL; + + ret = drv->probe(map); + + /* We decrease the use count here. It may have been a + probe-only module, which is no longer required from this + point, having given us a handle on (and increased the use + count of) the actual driver code. + */ + module_put(drv->module); + + return ret; +} +/* + * Destroy an MTD device which was created for a map device. + * Make sure the MTD device is already unregistered before calling this + */ +void map_destroy(struct mtd_info *mtd) +{ + struct map_info *map = mtd->priv; + + if (map->fldrv->destroy) + map->fldrv->destroy(mtd); + + module_put(map->fldrv->module); + + kfree(mtd); +} + +EXPORT_SYMBOL(register_mtd_chip_driver); +EXPORT_SYMBOL(unregister_mtd_chip_driver); +EXPORT_SYMBOL(do_map_probe); +EXPORT_SYMBOL(map_destroy); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("David Woodhouse "); +MODULE_DESCRIPTION("Core routines for registering and invoking MTD chip drivers"); -- cgit v1.3.1