diff options
Diffstat (limited to 'fs/read_write.c')
| -rw-r--r-- | fs/read_write.c | 33 |
1 files changed, 26 insertions, 7 deletions
diff --git a/fs/read_write.c b/fs/read_write.c index 74e36586e4d3..9cd9d148105d 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -31,6 +31,20 @@ const struct file_operations generic_ro_fops = { EXPORT_SYMBOL(generic_ro_fops); +static int +__negative_fpos_check(struct file *file, loff_t pos, size_t count) +{ + /* + * pos or pos+count is negative here, check overflow. + * too big "count" will be caught in rw_verify_area(). + */ + if ((pos < 0) && (pos + count < pos)) + return -EOVERFLOW; + if (file->f_mode & FMODE_UNSIGNED_OFFSET) + return 0; + return -EINVAL; +} + /** * generic_file_llseek_unlocked - lockless generic llseek implementation * @file: file structure to seek on @@ -62,7 +76,9 @@ generic_file_llseek_unlocked(struct file *file, loff_t offset, int origin) break; } - if (offset < 0 || offset > inode->i_sb->s_maxbytes) + if (offset < 0 && __negative_fpos_check(file, offset, 0)) + return -EINVAL; + if (offset > inode->i_sb->s_maxbytes) return -EINVAL; /* Special lock needed here? */ @@ -124,7 +140,7 @@ loff_t default_llseek(struct file *file, loff_t offset, int origin) { loff_t retval; - lock_kernel(); + mutex_lock(&file->f_dentry->d_inode->i_mutex); switch (origin) { case SEEK_END: offset += i_size_read(file->f_path.dentry->d_inode); @@ -137,7 +153,7 @@ loff_t default_llseek(struct file *file, loff_t offset, int origin) offset += file->f_pos; } retval = -EINVAL; - if (offset >= 0) { + if (offset >= 0 || !__negative_fpos_check(file, offset, 0)) { if (offset != file->f_pos) { file->f_pos = offset; file->f_version = 0; @@ -145,7 +161,7 @@ loff_t default_llseek(struct file *file, loff_t offset, int origin) retval = offset; } out: - unlock_kernel(); + mutex_unlock(&file->f_dentry->d_inode->i_mutex); return retval; } EXPORT_SYMBOL(default_llseek); @@ -156,7 +172,6 @@ loff_t vfs_llseek(struct file *file, loff_t offset, int origin) fn = no_llseek; if (file->f_mode & FMODE_LSEEK) { - fn = default_llseek; if (file->f_op && file->f_op->llseek) fn = file->f_op->llseek; } @@ -222,6 +237,7 @@ bad: } #endif + /* * rw_verify_area doesn't like huge counts. We limit * them to something that fits in "int" so that others @@ -239,8 +255,11 @@ int rw_verify_area(int read_write, struct file *file, loff_t *ppos, size_t count if (unlikely((ssize_t) count < 0)) return retval; pos = *ppos; - if (unlikely((pos < 0) || (loff_t) (pos + count) < 0)) - return retval; + if (unlikely((pos < 0) || (loff_t) (pos + count) < 0)) { + retval = __negative_fpos_check(file, pos, count); + if (retval) + return retval; + } if (unlikely(inode->i_flock && mandatory_lock(inode))) { retval = locks_mandatory_area( |