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authorGlauber de Oliveira Costa <glommer@br.ibm.com>2005-10-30 15:03:05 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2005-10-30 17:37:26 -0800
commit2973dfdb877c17b36c27ba66d71028ff1eb2f32e (patch)
tree9734599068f3fcf7cd33f948235588f7a275d193 /fs
parent7f04c26d715a2467a49a2384268de8f70f787b51 (diff)
[PATCH] Test for sb_getblk return value
This patch adds tests for the return value of sb_getblk() in the ext2/3 filesystems. In fs/buffer.c it is stated that the getblk() function never fails. However, it does can return NULL in some situations due to I/O errors, which may lead us to NULL pointer dereferences Signed-off-by: Glauber de Oliveira Costa <glommer@br.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/ext2/inode.c4
-rw-r--r--fs/ext3/inode.c9
-rw-r--r--fs/ext3/resize.c10
3 files changed, 22 insertions, 1 deletions
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index fdba4d1d3c60..e7d3f0522d01 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -440,6 +440,10 @@ static int ext2_alloc_branch(struct inode *inode,
* the pointer to new one, then send parent to disk.
*/
bh = sb_getblk(inode->i_sb, parent);
+ if (!bh) {
+ err = -EIO;
+ break;
+ }
lock_buffer(bh);
memset(bh->b_data, 0, blocksize);
branch[n].bh = bh;
diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index b5da5244e144..5d9b00e28837 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -523,7 +523,6 @@ static int ext3_alloc_branch(handle_t *handle, struct inode *inode,
if (!nr)
break;
branch[n].key = cpu_to_le32(nr);
- keys = n+1;
/*
* Get buffer_head for parent block, zero it out
@@ -531,6 +530,9 @@ static int ext3_alloc_branch(handle_t *handle, struct inode *inode,
* parent to disk.
*/
bh = sb_getblk(inode->i_sb, parent);
+ if (!bh)
+ break;
+ keys = n+1;
branch[n].bh = bh;
lock_buffer(bh);
BUFFER_TRACE(bh, "call get_create_access");
@@ -864,6 +866,10 @@ struct buffer_head *ext3_getblk(handle_t *handle, struct inode * inode,
if (!*errp && buffer_mapped(&dummy)) {
struct buffer_head *bh;
bh = sb_getblk(inode->i_sb, dummy.b_blocknr);
+ if (!bh) {
+ *errp = -EIO;
+ goto err;
+ }
if (buffer_new(&dummy)) {
J_ASSERT(create != 0);
J_ASSERT(handle != 0);
@@ -896,6 +902,7 @@ struct buffer_head *ext3_getblk(handle_t *handle, struct inode * inode,
}
return bh;
}
+err:
return NULL;
}
diff --git a/fs/ext3/resize.c b/fs/ext3/resize.c
index 57f79106267d..1be78b4b4de9 100644
--- a/fs/ext3/resize.c
+++ b/fs/ext3/resize.c
@@ -118,6 +118,8 @@ static struct buffer_head *bclean(handle_t *handle, struct super_block *sb,
int err;
bh = sb_getblk(sb, blk);
+ if (!bh)
+ return ERR_PTR(-EIO);
if ((err = ext3_journal_get_write_access(handle, bh))) {
brelse(bh);
bh = ERR_PTR(err);
@@ -202,6 +204,10 @@ static int setup_new_group_blocks(struct super_block *sb,
ext3_debug("update backup group %#04lx (+%d)\n", block, bit);
gdb = sb_getblk(sb, block);
+ if (!gdb) {
+ err = -EIO;
+ goto exit_bh;
+ }
if ((err = ext3_journal_get_write_access(handle, gdb))) {
brelse(gdb);
goto exit_bh;
@@ -643,6 +649,10 @@ static void update_backups(struct super_block *sb,
break;
bh = sb_getblk(sb, group * bpg + blk_off);
+ if (!bh) {
+ err = -EIO;
+ break;
+ }
ext3_debug("update metadata backup %#04lx\n",
(unsigned long)bh->b_blocknr);
if ((err = ext3_journal_get_write_access(handle, bh)))