fsdrv->truncate is dereferenced at times without checking for NULL before, leading to crashes, e.g. doing:
edit -o /mnt/myext4/FILE some text on ext4 crashes. Fix this by returning -EROFS when truncate is unimplemented. Reported-by: Xogium <[email protected]> Signed-off-by: Ahmad Fatoum <[email protected]> --- fs/fs.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/fs/fs.c b/fs/fs.c index a9dbf1dd4e2f..2f4b642b3952 100644 --- a/fs/fs.c +++ b/fs/fs.c @@ -208,9 +208,15 @@ int creat(const char *pathname, mode_t mode) } EXPORT_SYMBOL(creat); +static int fsdev_truncate(struct device_d *dev, FILE *f, loff_t length) +{ + struct fs_driver_d *fsdrv = f->fsdev->driver; + + return fsdrv->truncate ? fsdrv->truncate(&f->fsdev->dev, f, length) : -EROFS; +} + int ftruncate(int fd, loff_t length) { - struct fs_driver_d *fsdrv; FILE *f = fd_to_file(fd); int ret; @@ -220,9 +226,7 @@ int ftruncate(int fd, loff_t length) if (f->size == FILE_SIZE_STREAM) return 0; - fsdrv = f->fsdev->driver; - - ret = fsdrv->truncate(&f->fsdev->dev, f, length); + ret = fsdev_truncate(&f->fsdev->dev, f, length); if (ret) { errno = -ret; return ret; @@ -332,7 +336,7 @@ static ssize_t __write(FILE *f, const void *buf, size_t count) assert_command_context(); if (f->size != FILE_SIZE_STREAM && f->pos + count > f->size) { - ret = fsdrv->truncate(&f->fsdev->dev, f, f->pos + count); + ret = fsdev_truncate(&f->fsdev->dev, f, f->pos + count); if (ret) { if (ret != -ENOSPC) goto out; @@ -2463,7 +2467,7 @@ int open(const char *pathname, int flags, ...) } if (flags & O_TRUNC) { - error = fsdrv->truncate(&fsdev->dev, f, 0); + error = fsdev_truncate(&fsdev->dev, f, 0); f->size = 0; inode->i_size = 0; if (error) -- 2.32.0 _______________________________________________ barebox mailing list [email protected] http://lists.infradead.org/mailman/listinfo/barebox
