X-Git-Url: http://git.agner.ch/gitweb/?a=blobdiff_plain;f=fs%2Fbinfmt_aout.c;h=813a887cd2b3257d4b4b039091d0194c3a232721;hb=958b7f37ee0fb2846c8d44310a68ae9605614ff9;hp=72011826f0cb340aabc54f65ee7d31653fc7d364;hpb=2fc2991175bf77395e6b15fe6b2304d3bf72da40;p=linux-drm-fsl-dcu.git

diff --git a/fs/binfmt_aout.c b/fs/binfmt_aout.c
index 72011826f0cb..813a887cd2b3 100644
--- a/fs/binfmt_aout.c
+++ b/fs/binfmt_aout.c
@@ -33,8 +33,6 @@ static int load_aout_binary(struct linux_binprm *, struct pt_regs * regs);
 static int load_aout_library(struct file*);
 static int aout_core_dump(long signr, struct pt_regs * regs, struct file *file);
 
-extern void dump_thread(struct pt_regs *, struct user *);
-
 static struct linux_binfmt aout_format = {
 	.module		= THIS_MODULE,
 	.load_binary	= load_aout_binary,
@@ -276,10 +274,17 @@ static int load_aout_binary(struct linux_binprm * bprm, struct pt_regs * regs)
 	if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC &&
 	     N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) ||
 	    N_TRSIZE(ex) || N_DRSIZE(ex) ||
-	    i_size_read(bprm->file->f_dentry->d_inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
+	    i_size_read(bprm->file->f_path.dentry->d_inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
 		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
@@ -384,7 +389,7 @@ static int load_aout_binary(struct linux_binprm * bprm, struct pt_regs * regs)
 		{
 			printk(KERN_WARNING 
 			       "fd_offset is not page aligned. Please convert program: %s\n",
-			       bprm->file->f_dentry->d_name.name);
+			       bprm->file->f_path.dentry->d_name.name);
 			error_time = jiffies;
 		}
 
@@ -464,7 +469,7 @@ static int load_aout_library(struct file *file)
 	int retval;
 	struct exec ex;
 
-	inode = file->f_dentry->d_inode;
+	inode = file->f_path.dentry->d_inode;
 
 	retval = -ENOEXEC;
 	error = kernel_read(file, 0, (char *) &ex, sizeof(ex));
@@ -478,6 +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;
 
@@ -494,7 +506,7 @@ static int load_aout_library(struct file *file)
 		{
 			printk(KERN_WARNING 
 			       "N_TXTOFF is not page aligned. Please convert library: %s\n",
-			       file->f_dentry->d_name.name);
+			       file->f_path.dentry->d_name.name);
 			error_time = jiffies;
 		}
 		down_write(&current->mm->mmap_sem);