Messages in this thread Patch in this message |  | | Date | Thu, 17 Jan 2013 19:01:40 +0200 | Subject | Re: [PATCH 2/3] binfmt_elf: Verify signature of signed elf binary | From | "Kasatkin, Dmitry" <> |
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commit f6bf2c4c0339dabac435f518bb1fcb617fdef8f1 Author: Dmitry Kasatkin <dmitry.kasatkin@intel.com> Date: Thu Jan 17 18:50:43 2013 +0200
ima: lock down memory if binary is digitally signed
This patch set a flag in the linux_binprm structure if binary is digitally signed. The flag is used to lock down memory when loading ELF binary.
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 0c42cdb..ba94d13 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -44,6 +44,8 @@ #define user_siginfo_t siginfo_t #endif
+#define LSM_UNSAFE_DIGSIG 16 + static int load_elf_binary(struct linux_binprm *bprm); static int load_elf_library(struct file *); static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *, @@ -788,6 +790,9 @@ static int load_elf_binary(struct linux_binprm *bprm)
elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
+ if (bprm->unsafe & LSM_UNSAFE_DIGSIG) + elf_flags |= MAP_LOCKED; + vaddr = elf_ppnt->p_vaddr; if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) { elf_flags |= MAP_FIXED; diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index b359fb5..50d9959 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -27,6 +27,8 @@
#include "ima.h"
+#define LSM_UNSAFE_DIGSIG 16 + int ima_initialized;
#ifdef CONFIG_IMA_APPRAISE @@ -315,10 +317,19 @@ int ima_file_mmap(struct file *file, unsigned long prot) */ int ima_bprm_check(struct linux_binprm *bprm) { - return process_measurement(bprm->file, + int err; + struct integrity_iint_cache *iint; + + err = process_measurement(bprm->file, (strcmp(bprm->filename, bprm->interp) == 0) ? bprm->filename : bprm->interp, MAY_EXEC, BPRM_CHECK); + + iint = integrity_iint_find(bprm->file->f_dentry->d_inode); + if (iint && (iint->flags & IMA_DIGSIG)) + bprm->unsafe |= LSM_UNSAFE_DIGSIG; + + return err; }
/**
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