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authorEugene Teo <eteo@redhat.com>2006-09-29 01:59:33 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-09-29 09:18:08 -0700
commit8454aeef6fea944ced757ff8e761b59eb3ee960f (patch)
tree235e366e3744cdf76381d9e8a709d7564dde94e0
parent563d075702454f6fa745ff8b0db605c73478078e (diff)
downloadlinux-8454aeef6fea944ced757ff8e761b59eb3ee960f.tar.bz2
[PATCH] Require mmap handler for a.out executables
Files supported by fs/proc/base.c, i.e. /proc/<pid>/*, are not capable of meeting the validity checks in ELF load_elf_*() handling because they have no mmap handler which is required by ELF. In order to stop a.out executables being used as part of an exploit attack against /proc-related vulnerabilities, we make a.out executables depend on ->mmap() existing. Signed-off-by: Eugene Teo <eteo@redhat.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--fs/binfmt_aout.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/fs/binfmt_aout.c b/fs/binfmt_aout.c
index f312103434d4..517e111bb7ef 100644
--- a/fs/binfmt_aout.c
+++ b/fs/binfmt_aout.c
@@ -278,6 +278,13 @@ static int load_aout_binary(struct linux_binprm * bprm, struct pt_regs * regs)
return -ENOEXEC;
}
+ /*
+ * Requires a mmap handler. This prevents people from using a.out
+ * as part of an exploit attack against /proc-related vulnerabilities.
+ */
+ if (!bprm->file->f_op || !bprm->file->f_op->mmap)
+ return -ENOEXEC;
+
fd_offset = N_TXTOFF(ex);
/* Check initial limits. This avoids letting people circumvent
@@ -476,6 +483,13 @@ static int load_aout_library(struct file *file)
goto out;
}
+ /*
+ * Requires a mmap handler. This prevents people from using a.out
+ * as part of an exploit attack against /proc-related vulnerabilities.
+ */
+ if (!file->f_op || !file->f_op->mmap)
+ goto out;
+
if (N_FLAGS(ex))
goto out;