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 /include/linux/compat.h | |
| 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 'include/linux/compat.h')
| -rw-r--r-- | include/linux/compat.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/compat.h b/include/linux/compat.h index 233f61ec8afc..56cebaff0c91 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -608,7 +608,7 @@ asmlinkage long compat_sys_fstatfs(unsigned int fd, asmlinkage long compat_sys_fstatfs64(unsigned int fd, compat_size_t sz, struct compat_statfs64 __user *buf); asmlinkage long compat_sys_truncate(const char __user *, compat_off_t); -asmlinkage long compat_sys_ftruncate(unsigned int, compat_ulong_t); +asmlinkage long compat_sys_ftruncate(unsigned int, compat_off_t); /* No generic prototype for truncate64, ftruncate64, fallocate */ asmlinkage long compat_sys_openat(int dfd, const char __user *filename, int flags, umode_t mode); |