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| author | Andi Kleen <ak@linux.intel.com> | 2018-01-25 15:50:28 -0800 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-01-26 15:03:56 +0100 |
| commit | caf7501a1b4ec964190f31f9c3f163de252273b8 (patch) | |
| tree | f626e796eb8f30eca268595ca07dc90e00b06ec3 /kernel/module.c | |
| parent | c940a3fb1e2e9b7d03228ab28f375fb5a47ff699 (diff) | |
| download | linux-caf7501a1b4ec964190f31f9c3f163de252273b8.tar.gz linux-caf7501a1b4ec964190f31f9c3f163de252273b8.tar.bz2 linux-caf7501a1b4ec964190f31f9c3f163de252273b8.zip | |
module/retpoline: Warn about missing retpoline in module
There's a risk that a kernel which has full retpoline mitigations becomes
vulnerable when a module gets loaded that hasn't been compiled with the
right compiler or the right option.
To enable detection of that mismatch at module load time, add a module info
string "retpoline" at build time when the module was compiled with
retpoline support. This only covers compiled C source, but assembler source
or prebuilt object files are not checked.
If a retpoline enabled kernel detects a non retpoline protected module at
load time, print a warning and report it in the sysfs vulnerability file.
[ tglx: Massaged changelog ]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: gregkh@linuxfoundation.org
Cc: torvalds@linux-foundation.org
Cc: jeyu@kernel.org
Cc: arjan@linux.intel.com
Link: https://lkml.kernel.org/r/20180125235028.31211-1-andi@firstfloor.org
Diffstat (limited to 'kernel/module.c')
| -rw-r--r-- | kernel/module.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/kernel/module.c b/kernel/module.c index de66ec825992..690c0651c40f 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2855,6 +2855,15 @@ static int check_modinfo_livepatch(struct module *mod, struct load_info *info) } #endif /* CONFIG_LIVEPATCH */ +static void check_modinfo_retpoline(struct module *mod, struct load_info *info) +{ + if (retpoline_module_ok(get_modinfo(info, "retpoline"))) + return; + + pr_warn("%s: loading module not compiled with retpoline compiler.\n", + mod->name); +} + /* Sets info->hdr and info->len. */ static int copy_module_from_user(const void __user *umod, unsigned long len, struct load_info *info) @@ -3021,6 +3030,8 @@ static int check_modinfo(struct module *mod, struct load_info *info, int flags) add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK); } + check_modinfo_retpoline(mod, info); + if (get_modinfo(info, "staging")) { add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK); pr_warn("%s: module is from the staging directory, the quality " |