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46752820f9
The ELF ".gnu.linkonce.this_module" section is special, it is what we use to construct the struct module __this_module, which THIS_MODULE points to. When userspace loads a module we always deal first with a copy of the userspace buffer, and twiddle with the userspace copy's version of the struct module. Eventually we allocate memory to do a memcpy() of that struct module, under the assumption that the module size is right. But we have no validity checks against the size or the requirements for the section. Add some validity checks for the special module section early and while at it, cache the module section index early, so we don't have to do that later. While at it, just move over the assigment of the info->mod to make the code clearer. The validity checker also adds an explicit size check to ensure the module section size matches the kernel's run time size for sizeof(struct module). This should prevent sloppy loads of modules which are built today *without* actually increasing the size of the struct module. A developer today can for example expand the size of struct module, rebuild a directoroy 'make fs/xfs/' for example and then try to insmode the driver there. That module would in effect have an incorrect size. This new size check would put a stop gap against such mistakes. This also makes the entire goal of ".gnu.linkonce.this_module" pretty clear. Before this patch verification of the goal / intent required some Indian Jones whips, torches and cleaning up big old spider webs. Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> |
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| .. | ||
| debug_kmemleak.c | ||
| decompress.c | ||
| internal.h | ||
| kallsyms.c | ||
| Kconfig | ||
| kdb.c | ||
| livepatch.c | ||
| main.c | ||
| Makefile | ||
| procfs.c | ||
| signing.c | ||
| strict_rwx.c | ||
| sysfs.c | ||
| tracking.c | ||
| tree_lookup.c | ||
| version.c | ||