user/sven/linux.git/kernel/module.c, branch v4.19.176

module: delay kobject uevent until after module init call

2021-01-06T13:45:01Z

[ Upstream commit 38dc717e97153e46375ee21797aa54777e5498f3 ] Apparently there has been a longstanding race between udev/systemd and the module loader. Currently, the module loader sends a uevent right after sysfs initialization, but before the module calls its init function. However, some udev rules expect that the module has initialized already upon receiving the uevent. This race has been triggered recently (see link in references) in some systemd mount unit files. For instance, the configfs module creates the /sys/kernel/config mount point in its init function, however the module loader issues the uevent before this happens. sys-kernel-config.mount expects to be able to mount /sys/kernel/config upon receipt of the module loading uevent, but if the configfs module has not called its init function yet, then this directory will not exist and the mount unit fails. A similar situation exists for sys-fs-fuse-connections.mount, as the fuse sysfs mount point is created during the fuse module's init function. If udev is faster than module initialization then the mount unit would fail in a similar fashion. To fix this race, delay the module KOBJ_ADD uevent until after the module has finished calling its init routine. References: https://github.com/systemd/systemd/issues/17586 Reviewed-by: Greg Kroah-Hartman Tested-By: Nicolas Morey-Chaisemartin Signed-off-by: Jessica Yu Signed-off-by: Sasha Levin

module: set MODULE_STATE_GOING state when a module fails to load

2021-01-06T13:45:01Z

[ Upstream commit 5e8ed280dab9eeabc1ba0b2db5dbe9fe6debb6b5 ] If a module fails to load due to an error in prepare_coming_module(), the following error handling in load_module() runs with MODULE_STATE_COMING in module's state. Fix it by correctly setting MODULE_STATE_GOING under "bug_cleanup" label. Signed-off-by: Miroslav Benes Signed-off-by: Jessica Yu Signed-off-by: Sasha Levin

module: Correctly truncate sysfs sections output

2020-08-21T09:05:34Z

commit 11990a5bd7e558e9203c1070fc52fb6f0488e75b upstream. The only-root-readable /sys/module/$module/sections/$section files did not truncate their output to the available buffer size. While most paths into the kernfs read handlers end up using PAGE_SIZE buffers, it's possible to get there through other paths (e.g. splice, sendfile). Actually limit the output to the "count" passed into the read function, and report it back correctly. *sigh* Reported-by: kernel test robot Link: https://lore.kernel.org/lkml/20200805002015.GE23458@shao2-debian Fixes: ed66f991bb19 ("module: Refactor section attr into bin attribute") Cc: stable@vger.kernel.org Reviewed-by: Greg Kroah-Hartman Acked-by: Jessica Yu Signed-off-by: Kees Cook Signed-off-by: Greg Kroah-Hartman

module: Do not expose section addresses to non-CAP_SYSLOG

2020-07-16T06:17:26Z

commit b25a7c5af9051850d4f3d93ca500056ab6ec724b upstream. The printing of section addresses in /sys/module/*/sections/* was not using the correct credentials to evaluate visibility. Before: # cat /sys/module/*/sections/.*text 0xffffffffc0458000 ... # capsh --drop=CAP_SYSLOG -- -c "cat /sys/module/*/sections/.*text" 0xffffffffc0458000 ... After: # cat /sys/module/*/sections/*.text 0xffffffffc0458000 ... # capsh --drop=CAP_SYSLOG -- -c "cat /sys/module/*/sections/.*text" 0x0000000000000000 ... Additionally replaces the existing (safe) /proc/modules check with file->f_cred for consistency. Reported-by: Dominik Czarnota Fixes: be71eda5383f ("module: Fix display of wrong module .text address") Cc: stable@vger.kernel.org Tested-by: Jessica Yu Acked-by: Jessica Yu Signed-off-by: Kees Cook Signed-off-by: Greg Kroah-Hartman

module: Refactor section attr into bin attribute

2020-07-16T06:17:26Z

commit ed66f991bb19d94cae5d38f77de81f96aac7813f upstream. In order to gain access to the open file's f_cred for kallsym visibility permission checks, refactor the module section attributes to use the bin_attribute instead of attribute interface. Additionally removes the redundant "name" struct member. Cc: stable@vger.kernel.org Reviewed-by: Greg Kroah-Hartman Tested-by: Jessica Yu Acked-by: Jessica Yu Signed-off-by: Kees Cook Signed-off-by: Greg Kroah-Hartman

kernel: module: Use struct_size() helper

2020-07-16T06:17:26Z

commit 8d1b73dd25ff92c3fa9807a20c22fa2b44c07336 upstream. One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example: struct module_sect_attrs { ... struct module_sect_attr attrs[0]; }; Make use of the struct_size() helper instead of an open-coded version in order to avoid any potential type mistakes. So, replace the following form: sizeof(*sect_attrs) + nloaded * sizeof(sect_attrs->attrs[0] with: struct_size(sect_attrs, attrs, nloaded) This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva Signed-off-by: Jessica Yu Signed-off-by: Greg Kroah-Hartman

kallsyms: Refactor kallsyms_show_value() to take cred

2020-07-16T06:17:26Z

commit 160251842cd35a75edfb0a1d76afa3eb674ff40a upstream. In order to perform future tests against the cred saved during open(), switch kallsyms_show_value() to operate on a cred, and have all current callers pass current_cred(). This makes it very obvious where callers are checking the wrong credential in their "read" contexts. These will be fixed in the coming patches. Additionally switch return value to bool, since it is always used as a direct permission check, not a 0-on-success, negative-on-error style function return. Cc: stable@vger.kernel.org Signed-off-by: Kees Cook Signed-off-by: Greg Kroah-Hartman

module: avoid setting info->name early in case we can fall back to info->mod->name

2020-02-24T07:34:49Z

[ Upstream commit 708e0ada1916be765b7faa58854062f2bc620bbf ] In setup_load_info(), info->name (which contains the name of the module, mostly used for early logging purposes before the module gets set up) gets unconditionally assigned if .modinfo is missing despite the fact that there is an if (!info->name) check near the end of the function. Avoid assigning a placeholder string to info->name if .modinfo doesn't exist, so that we can fall back to info->mod->name later on. Fixes: 5fdc7db6448a ("module: setup load info before module_sig_check()") Reviewed-by: Miroslav Benes Signed-off-by: Jessica Yu Signed-off-by: Sasha Levin

kernel/module: Fix memleak in module_add_modinfo_attrs()

2020-02-11T12:33:50Z

[ Upstream commit f6d061d617124abbd55396a3bc37b9bf7d33233c ] In module_add_modinfo_attrs() if sysfs_create_file() fails on the first iteration of the loop (so i = 0), we forget to free the modinfo_attrs. Fixes: bc6f2a757d52 ("kernel/module: Fix mem leak in module_add_modinfo_attrs") Reviewed-by: Miroslav Benes Signed-off-by: YueHaibing Signed-off-by: Jessica Yu Signed-off-by: Sasha Levin

kernel/module.c: wakeup processes in module_wq on module unload

2019-12-17T19:35:57Z

[ Upstream commit 5d603311615f612320bb77bd2a82553ef1ced5b7 ] Fix the race between load and unload a kernel module. sys_delete_module() try_stop_module() mod->state = _GOING add_unformed_module() old = find_module_all() (old->state == _GOING => wait_event_interruptible()) During pre-condition finished_loading() rets 0 schedule() (never gets waken up later) free_module() mod->state = _UNFORMED list_del_rcu(&mod->list) (dels mod from "modules" list) return The race above leads to modprobe hanging forever on loading a module. Error paths on loading module call wake_up_all(&module_wq) after freeing module, so let's do the same on straight module unload. Fixes: 6e6de3dee51a ("kernel/module.c: Only return -EEXIST for modules that have finished loading") Reviewed-by: Prarit Bhargava Signed-off-by: Konstantin Khorenko Signed-off-by: Jessica Yu Signed-off-by: Sasha Levin