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| author | Eric Paris <eparis@redhat.com> | 2009-07-31 12:54:05 -0400 |
|---|---|---|
| committer | James Morris <jmorris@namei.org> | 2009-08-17 15:08:48 +1000 |
| commit | 8cf948e744e0218af604c32edecde10006dc8e9e (patch) | |
| tree | c5d48e9210976e28e5ce07d69ca9b87d4c437389 /security/selinux | |
| parent | 9c0d90103c7e0eb6e638e5b649e9f6d8d9c1b4b3 (diff) | |
| download | linux-stable-8cf948e744e0218af604c32edecde10006dc8e9e.tar.gz linux-stable-8cf948e744e0218af604c32edecde10006dc8e9e.tar.bz2 linux-stable-8cf948e744e0218af604c32edecde10006dc8e9e.zip | |
SELinux: call cap_file_mmap in selinux_file_mmap
Currently SELinux does not check CAP_SYS_RAWIO in the file_mmap hook. This
means there is no DAC check on the ability to mmap low addresses in the
memory space. This function adds the DAC check for CAP_SYS_RAWIO while
maintaining the selinux check on mmap_zero. This means that processes
which need to mmap low memory will need CAP_SYS_RAWIO and mmap_zero but will
NOT need the SELinux sys_rawio capability.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'security/selinux')
| -rw-r--r-- | security/selinux/hooks.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 1e8cfc4c2ed6..e6d1432b0800 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3030,9 +3030,21 @@ static int selinux_file_mmap(struct file *file, unsigned long reqprot, int rc = 0; u32 sid = current_sid(); - if (addr < mmap_min_addr) + /* + * notice that we are intentionally putting the SELinux check before + * the secondary cap_file_mmap check. This is such a likely attempt + * at bad behaviour/exploit that we always want to get the AVC, even + * if DAC would have also denied the operation. + */ + if (addr < mmap_min_addr) { rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT, MEMPROTECT__MMAP_ZERO, NULL); + if (rc) + return rc; + } + + /* do DAC check on address space usage */ + rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only); if (rc || addr_only) return rc; |