| Message ID | 20180702004124.13042-2-xypron.glpk@gmx.de |
|---|---|
| State | Accepted |
| Delegated to: | Alexander Graf |
| Headers | show |
| Series | efi_loader: allow writing to FAT | expand |
Hi Heinrich, On 1 July 2018 at 17:41, Heinrich Schuchardt <xypron.glpk@gmx.de> wrote: > fs_fat_write() is not able to write to subdirectories. > > Currently if a filepath with a leading slash is passed, the slash is > treated as part of the filename to be created in the root directory. > > Strip leading (back-)slashes. > > Check that the remaining filename does not contain any illegal characters > (<>:"/\|?*). This way we will throw an error when trying to write to a > subdirectory. > > Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> > --- > fs/fat/fat_write.c | 16 +++++++++++++++- > 1 file changed, 15 insertions(+), 1 deletion(-) It would be great if we have filesystem tests. We do have the fs-test.sh script but it is not using pytest, so best not to build on it. Regards, Simon
On 07/09/2018 04:35 AM, Simon Glass wrote: > Hi Heinrich, > > On 1 July 2018 at 17:41, Heinrich Schuchardt <xypron.glpk@gmx.de> wrote: >> fs_fat_write() is not able to write to subdirectories. >> >> Currently if a filepath with a leading slash is passed, the slash is >> treated as part of the filename to be created in the root directory. >> >> Strip leading (back-)slashes. >> >> Check that the remaining filename does not contain any illegal characters >> (<>:"/\|?*). This way we will throw an error when trying to write to a >> subdirectory. >> >> Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> >> --- >> fs/fat/fat_write.c | 16 +++++++++++++++- >> 1 file changed, 15 insertions(+), 1 deletion(-) > > It would be great if we have filesystem tests. We do have the > fs-test.sh script but it is not using pytest, so best not to build on > it. There is a write test for FAT in lib/efi_selftest/efi_selftest_block_device.c. See patch "efi_selftest: test writing to file". I agree having tests independent of the EFI subsystem would be a good idea. Best regards Heinrich
diff --git a/fs/fat/fat_write.c b/fs/fat/fat_write.c index 5ca8fcda73..c5aee519b7 100644 --- a/fs/fat/fat_write.c +++ b/fs/fat/fat_write.c @@ -908,9 +908,11 @@ static int do_fat_write(const char *filename, void *buffer, loff_t size, volume_info volinfo; fsdata datablock; fsdata *mydata = &datablock; - int cursect; + int cursect, i; int ret = -1, name_len; char l_filename[VFAT_MAXLEN_BYTES]; + char bad[2] = " "; + const char illegal[] = "<>:\"/\\|?*"; *actwrite = size; dir_curclust = 0; @@ -970,6 +972,18 @@ static int do_fat_write(const char *filename, void *buffer, loff_t size, } dentptr = (dir_entry *) do_fat_read_at_block; + /* Strip leading (back-)slashes */ + while ISDIRDELIM(*filename) + ++filename; + /* Check that the filename is valid */ + for (i = 0; i < strlen(illegal); ++i) { + *bad = illegal[i]; + if (strstr(filename, bad)) { + printf("FAT: illegal filename (%s)\n", filename); + return -1; + } + } + name_len = strlen(filename); if (name_len >= VFAT_MAXLEN_BYTES) name_len = VFAT_MAXLEN_BYTES - 1;
fs_fat_write() is not able to write to subdirectories. Currently if a filepath with a leading slash is passed, the slash is treated as part of the filename to be created in the root directory. Strip leading (back-)slashes. Check that the remaining filename does not contain any illegal characters (<>:"/\|?*). This way we will throw an error when trying to write to a subdirectory. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> --- fs/fat/fat_write.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-)