X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=fs%2Fbinfmt_aout.c;h=7596e1e94cde858df0ba7ea0907f9b86d1f4132e;hb=614ee1f61f667b02165c1ae0c1357048dc6d94a0;hp=f312103434d4594fcd8d532c90bb8b4cf4698289;hpb=9fdb62af92c741addbea15545f214a6e89460865;p=linux-2.6-omap-h63xx.git

diff --git a/fs/binfmt_aout.c b/fs/binfmt_aout.c
index f312103434d..7596e1e94cd 100644
--- a/fs/binfmt_aout.c
+++ b/fs/binfmt_aout.c
@@ -31,7 +31,7 @@
 
 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);
+static int aout_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit);
 
 static struct linux_binfmt aout_format = {
 	.module		= THIS_MODULE,
@@ -88,7 +88,7 @@ if (file->f_op->llseek) { \
  * dumping of the process results in another error..
  */
 
-static int aout_core_dump(long signr, struct pt_regs * regs, struct file *file)
+static int aout_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit)
 {
 	mm_segment_t fs;
 	int has_dumped = 0;
@@ -123,23 +123,19 @@ static int aout_core_dump(long signr, struct pt_regs * regs, struct file *file)
 /* If the size of the dump file exceeds the rlimit, then see what would happen
    if we wrote the stack, but not the data area.  */
 #ifdef __sparc__
-	if ((dump.u_dsize+dump.u_ssize) >
-	    current->signal->rlim[RLIMIT_CORE].rlim_cur)
+	if ((dump.u_dsize + dump.u_ssize) > limit)
 		dump.u_dsize = 0;
 #else
-	if ((dump.u_dsize+dump.u_ssize+1) * PAGE_SIZE >
-	    current->signal->rlim[RLIMIT_CORE].rlim_cur)
+	if ((dump.u_dsize + dump.u_ssize+1) * PAGE_SIZE > limit)
 		dump.u_dsize = 0;
 #endif
 
 /* Make sure we have enough room to write the stack and data areas. */
 #ifdef __sparc__
-	if ((dump.u_ssize) >
-	    current->signal->rlim[RLIMIT_CORE].rlim_cur)
+	if (dump.u_ssize > limit)
 		dump.u_ssize = 0;
 #else
-	if ((dump.u_ssize+1) * PAGE_SIZE >
-	    current->signal->rlim[RLIMIT_CORE].rlim_cur)
+	if ((dump.u_ssize + 1) * PAGE_SIZE > limit)
 		dump.u_ssize = 0;
 #endif
 
@@ -274,10 +270,17 @@ 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
@@ -316,7 +319,6 @@ static int load_aout_binary(struct linux_binprm * bprm, struct pt_regs * regs)
 	current->mm->free_area_cache = current->mm->mmap_base;
 	current->mm->cached_hole_size = 0;
 
-	current->mm->mmap = NULL;
 	compute_creds(bprm);
  	current->flags &= ~PF_FORKNOEXEC;
 #ifdef __sparc__
@@ -382,7 +384,7 @@ 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;
 		}
 
@@ -462,7 +464,7 @@ 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));
@@ -476,6 +478,13 @@ 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;
 
@@ -492,7 +501,7 @@ 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);