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| 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 /include/linux/compat.h | |
| 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 '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 1cfa4f0f490a..5981d3eadaee 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -609,7 +609,7 @@ 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); |