ftruncate: pass a signed offset

stable inclusion
from stable-v4.19.316
commit c329760749b5419769e57cb2be80955d2805f9c9
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAGEOW
CVE: CVE-2024-42084

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=tags/v4.19.317&id=c329760749b5419769e57cb2be80955d2805f9c9



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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: 3f6d078d ("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>
Signed-off-by: Long Li <leo.lilong@huawei.com>