diff options
| author | Arnd Bergmann <arnd@arndb.de> | 2024-06-19 11:34:09 +0200 |
|---|---|---|
| committer | Arnd Bergmann <arnd@arndb.de> | 2024-06-24 18:29:20 +0200 |
| commit | 4b8e88e563b5f666446d002ad0dc1e6e8e7102b0 (patch) | |
| tree | 4a3b1870dc71d4f2d867bf0217465c451f40c2a3 /fs/open.c | |
| parent | f2661062f16b2de5d7b6a5c42a9a5c96326b8454 (diff) | |
ftruncate: pass a signed offset
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>
Diffstat (limited to 'fs/open.c')
| -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 89cafb572061..50e45bc7c4d8 100644 --- a/fs/open.c +++ b/fs/open.c @@ -202,13 +202,13 @@ long do_sys_ftruncate(unsigned int fd, loff_t length, int small) 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); } |