udf: refactor inode_bmap() to handle error

Refactor inode_bmap() to handle error since udf_next_aext() can return
error now. On situations like ftruncate, udf_extend_file() can now
detect errors and bail out early without resorting to checking for
particular offsets and assuming internal behavior of these functions.

Reported-by: syzbot+7a4842f0b1801230a989@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=7a4842f0b1801230a989
Tested-by: syzbot+7a4842f0b1801230a989@syzkaller.appspotmail.com
Signed-off-by: Zhao Mengmeng <zhaomengmeng@kylinos.cn>
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20241001115425.266556-4-zhaomzhao@126.com
This commit is contained in:
Zhao Mengmeng 2024-10-01 19:54:25 +08:00 committed by Jan Kara
parent b405c1e58b
commit c226964ec7
5 changed files with 44 additions and 26 deletions

View File

@ -246,6 +246,7 @@ int udf_fiiter_init(struct udf_fileident_iter *iter, struct inode *dir,
{
struct udf_inode_info *iinfo = UDF_I(dir);
int err = 0;
int8_t etype;
iter->dir = dir;
iter->bh[0] = iter->bh[1] = NULL;
@ -265,9 +266,9 @@ int udf_fiiter_init(struct udf_fileident_iter *iter, struct inode *dir,
goto out;
}
if (inode_bmap(dir, iter->pos >> dir->i_blkbits, &iter->epos,
&iter->eloc, &iter->elen, &iter->loffset) !=
(EXT_RECORDED_ALLOCATED >> 30)) {
err = inode_bmap(dir, iter->pos >> dir->i_blkbits, &iter->epos,
&iter->eloc, &iter->elen, &iter->loffset, &etype);
if (err <= 0 || etype != (EXT_RECORDED_ALLOCATED >> 30)) {
if (pos == dir->i_size)
return 0;
udf_err(dir->i_sb,
@ -463,6 +464,7 @@ int udf_fiiter_append_blk(struct udf_fileident_iter *iter)
sector_t block;
uint32_t old_elen = iter->elen;
int err;
int8_t etype;
if (WARN_ON_ONCE(iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB))
return -EINVAL;
@ -477,8 +479,9 @@ int udf_fiiter_append_blk(struct udf_fileident_iter *iter)
udf_fiiter_update_elen(iter, old_elen);
return err;
}
if (inode_bmap(iter->dir, block, &iter->epos, &iter->eloc, &iter->elen,
&iter->loffset) != (EXT_RECORDED_ALLOCATED >> 30)) {
err = inode_bmap(iter->dir, block, &iter->epos, &iter->eloc, &iter->elen,
&iter->loffset, &etype);
if (err <= 0 || etype != (EXT_RECORDED_ALLOCATED >> 30)) {
udf_err(iter->dir->i_sb,
"block %llu not allocated in directory (ino %lu)\n",
(unsigned long long)block, iter->dir->i_ino);

View File

@ -404,7 +404,7 @@ struct udf_map_rq {
static int udf_map_block(struct inode *inode, struct udf_map_rq *map)
{
int err;
int ret;
struct udf_inode_info *iinfo = UDF_I(inode);
if (WARN_ON_ONCE(iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB))
@ -416,18 +416,24 @@ static int udf_map_block(struct inode *inode, struct udf_map_rq *map)
uint32_t elen;
sector_t offset;
struct extent_position epos = {};
int8_t etype;
down_read(&iinfo->i_data_sem);
if (inode_bmap(inode, map->lblk, &epos, &eloc, &elen, &offset)
== (EXT_RECORDED_ALLOCATED >> 30)) {
ret = inode_bmap(inode, map->lblk, &epos, &eloc, &elen, &offset,
&etype);
if (ret < 0)
goto out_read;
if (ret > 0 && etype == (EXT_RECORDED_ALLOCATED >> 30)) {
map->pblk = udf_get_lb_pblock(inode->i_sb, &eloc,
offset);
map->oflags |= UDF_BLK_MAPPED;
ret = 0;
}
out_read:
up_read(&iinfo->i_data_sem);
brelse(epos.bh);
return 0;
return ret;
}
down_write(&iinfo->i_data_sem);
@ -438,9 +444,9 @@ static int udf_map_block(struct inode *inode, struct udf_map_rq *map)
if (((loff_t)map->lblk) << inode->i_blkbits >= iinfo->i_lenExtents)
udf_discard_prealloc(inode);
udf_clear_extent_cache(inode);
err = inode_getblk(inode, map);
ret = inode_getblk(inode, map);
up_write(&iinfo->i_data_sem);
return err;
return ret;
}
static int __udf_get_block(struct inode *inode, sector_t block,
@ -662,8 +668,10 @@ static int udf_extend_file(struct inode *inode, loff_t newsize)
*/
udf_discard_prealloc(inode);
etype = inode_bmap(inode, first_block, &epos, &eloc, &elen, &offset);
within_last_ext = (etype != -1);
err = inode_bmap(inode, first_block, &epos, &eloc, &elen, &offset, &etype);
if (err < 0)
goto out;
within_last_ext = (err == 1);
/* We don't expect extents past EOF... */
WARN_ON_ONCE(within_last_ext &&
elen > ((loff_t)offset + 1) << inode->i_blkbits);
@ -2401,13 +2409,15 @@ int8_t udf_delete_aext(struct inode *inode, struct extent_position epos)
return (elen >> 30);
}
int8_t inode_bmap(struct inode *inode, sector_t block,
struct extent_position *pos, struct kernel_lb_addr *eloc,
uint32_t *elen, sector_t *offset)
/*
* Returns 1 on success, -errno on error, 0 on hit EOF.
*/
int inode_bmap(struct inode *inode, sector_t block, struct extent_position *pos,
struct kernel_lb_addr *eloc, uint32_t *elen, sector_t *offset,
int8_t *etype)
{
unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;
loff_t lbcount = 0, bcount = (loff_t) block << blocksize_bits;
int8_t etype;
struct udf_inode_info *iinfo;
int err = 0;
@ -2419,13 +2429,13 @@ int8_t inode_bmap(struct inode *inode, sector_t block,
}
*elen = 0;
do {
err = udf_next_aext(inode, pos, eloc, elen, &etype, 1);
err = udf_next_aext(inode, pos, eloc, elen, etype, 1);
if (err <= 0) {
if (err == 0) {
*offset = (bcount - lbcount) >> blocksize_bits;
iinfo->i_lenExtents = lbcount;
}
return -1;
return err;
}
lbcount += *elen;
} while (lbcount <= bcount);
@ -2433,5 +2443,5 @@ int8_t inode_bmap(struct inode *inode, sector_t block,
udf_update_extent_cache(inode, lbcount - *elen, pos);
*offset = (bcount + *elen - lbcount) >> blocksize_bits;
return etype;
return 1;
}

View File

@ -282,9 +282,11 @@ static uint32_t udf_try_read_meta(struct inode *inode, uint32_t block,
sector_t ext_offset;
struct extent_position epos = {};
uint32_t phyblock;
int8_t etype;
int err = 0;
if (inode_bmap(inode, block, &epos, &eloc, &elen, &ext_offset) !=
(EXT_RECORDED_ALLOCATED >> 30))
err = inode_bmap(inode, block, &epos, &eloc, &elen, &ext_offset, &etype);
if (err <= 0 || etype != (EXT_RECORDED_ALLOCATED >> 30))
phyblock = 0xFFFFFFFF;
else {
map = &UDF_SB(sb)->s_partmaps[partition];

View File

@ -214,10 +214,12 @@ int udf_truncate_extents(struct inode *inode)
else
BUG();
etype = inode_bmap(inode, first_block, &epos, &eloc, &elen, &offset);
ret = inode_bmap(inode, first_block, &epos, &eloc, &elen, &offset, &etype);
if (ret < 0)
return ret;
byte_offset = (offset << sb->s_blocksize_bits) +
(inode->i_size & (sb->s_blocksize - 1));
if (etype == -1) {
if (ret == 0) {
/* We should extend the file? */
WARN_ON(byte_offset);
return 0;

View File

@ -157,8 +157,9 @@ extern struct buffer_head *udf_bread(struct inode *inode, udf_pblk_t block,
extern int udf_setsize(struct inode *, loff_t);
extern void udf_evict_inode(struct inode *);
extern int udf_write_inode(struct inode *, struct writeback_control *wbc);
extern int8_t inode_bmap(struct inode *, sector_t, struct extent_position *,
struct kernel_lb_addr *, uint32_t *, sector_t *);
extern int inode_bmap(struct inode *inode, sector_t block,
struct extent_position *pos, struct kernel_lb_addr *eloc,
uint32_t *elen, sector_t *offset, int8_t *etype);
int udf_get_block(struct inode *, sector_t, struct buffer_head *, int);
extern int udf_setup_indirect_aext(struct inode *inode, udf_pblk_t block,
struct extent_position *epos);