diff options
| author | Arnd Bergmann <arnd@arndb.de> | 2024-06-19 12:34:09 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-07-05 10:34:04 +0300 |
| commit | 836359247b0403e0634bfbc83e5bb8063fad287a (patch) | |
| tree | e52c92f5c7c400fd173496349ad38f453dcd1e93 /fs | |
| parent | 062e256516d7db5e7dcdef117f52025cd5c456e3 (diff) | |
| download | linux-836359247b0403e0634bfbc83e5bb8063fad287a.tar.xz | |
ftruncate: pass a signed offset
commit 4b8e88e563b5f666446d002ad0dc1e6e8e7102b0 upstream.
The old ftruncate() syscall, using the 32-bit off_t misses a sign
extension when called in compat mode on 64-bit architectures. As a
result, passing a negative length accidentally succeeds in truncating
to file size between 2GiB and 4GiB.
Changing the type of the compat syscall to the signed compat_off_t
changes the behavior so it instead returns -EINVAL.
The native entry point, the truncate() syscall and the corresponding
loff_t based variants are all correct already and do not suffer
from this mistake.
Fixes: 3f6d078d4acc ("fix compat truncate/ftruncate")
Reviewed-by: Christian Brauner <brauner@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/open.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/open.c b/fs/open.c index 54723fceb776..59db720693f9 100644 --- a/fs/open.c +++ b/fs/open.c @@ -200,13 +200,13 @@ out: return error; } -SYSCALL_DEFINE2(ftruncate, unsigned int, fd, unsigned long, length) +SYSCALL_DEFINE2(ftruncate, unsigned int, fd, off_t, length) { return do_sys_ftruncate(fd, length, 1); } #ifdef CONFIG_COMPAT -COMPAT_SYSCALL_DEFINE2(ftruncate, unsigned int, fd, compat_ulong_t, length) +COMPAT_SYSCALL_DEFINE2(ftruncate, unsigned int, fd, compat_off_t, length) { return do_sys_ftruncate(fd, length, 1); } |