[PATCH] FAT/VFAT memory corruption during mount()

From: Petr Vandrovec (vandrove@vc.cvut.cz)
Date: Wed Oct 02 2002 - 14:16:37 EST


Hi Linus,

This patch fixes memory corruption during vfat mount: one byte
before mount options is overwritten by ',' since strtok->strsep
conversion happened.

This patch also fixes another problem introduced by strtok->strsep
conversion: VFAT requires that FAT does not modify passed options,
but unfortunately FAT driver fails to preserve options string if
there is more than one consecutive comma in option string.

                                        Thanks,
                                                Petr Vandrovec
                                                vandrove@vc.cvut.cz

diff -urdN linux/fs/fat/inode.c linux/fs/fat/inode.c
--- linux/fs/fat/inode.c 2002-10-02 13:20:19.000000000 +0200
+++ linux/fs/fat/inode.c 2002-10-02 19:54:59.000000000 +0200
@@ -228,8 +228,6 @@
         save = 0;
         savep = NULL;
         while ((this_char = strsep(&options,",")) != NULL) {
- if (!*this_char)
- continue;
                 if ((value = strchr(this_char,'=')) != NULL) {
                         save = *value;
                         savep = value;
@@ -351,7 +349,7 @@
                         strncpy(cvf_options,value,100);
                 }
 
- if (this_char != options) *(this_char-1) = ',';
+ if (options) *(options-1) = ',';
                 if (value) *savep = save;
                 if (ret == 0)
                         break;
diff -urdN linux/fs/vfat/namei.c linux/fs/vfat/namei.c
--- linux/fs/vfat/namei.c 2002-10-02 13:20:27.000000000 +0200
+++ linux/fs/vfat/namei.c 2002-10-02 19:54:28.000000000 +0200
@@ -117,8 +117,6 @@
         savep = NULL;
         ret = 1;
         while ((this_char = strsep(&options,",")) != NULL) {
- if (!*this_char)
- continue;
                 if ((value = strchr(this_char,'=')) != NULL) {
                         save = *value;
                         savep = value;
@@ -154,8 +152,8 @@
                         else
                                 ret = 0;
                 }
- if (this_char != options)
- *(this_char-1) = ',';
+ if (options)
+ *(options-1) = ',';
                 if (value) {
                         *savep = save;
                 }
-
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This archive was generated by hypermail 2b29 : Mon Oct 07 2002 - 22:00:35 EST