From db218fdfcf16b664c990f02c94ed89ac2c1ad314 Mon Sep 17 00:00:00 2001 From: Andrei Vagin Date: Thu, 3 Oct 2019 13:35:24 -0700 Subject: Don't report partialResult errors from sendfile The input file descriptor is always a regular file, so sendfile can't lose any data if it will not be able to write them to the output file descriptor. Reported-by: syzbot+22d22330a35fa1c02155@syzkaller.appspotmail.com PiperOrigin-RevId: 272730357 --- pkg/sentry/syscalls/linux/sys_splice.go | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) (limited to 'pkg/sentry/syscalls') diff --git a/pkg/sentry/syscalls/linux/sys_splice.go b/pkg/sentry/syscalls/linux/sys_splice.go index 9f705ebca..dd3a5807f 100644 --- a/pkg/sentry/syscalls/linux/sys_splice.go +++ b/pkg/sentry/syscalls/linux/sys_splice.go @@ -159,9 +159,14 @@ func Sendfile(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc }, outFile.Flags().NonBlocking) } + // Sendfile can't lose any data because inFD is always a regual file. + if n != 0 { + err = nil + } + // We can only pass a single file to handleIOError, so pick inFile // arbitrarily. This is used only for debugging purposes. - return uintptr(n), nil, handleIOError(t, n != 0, err, kernel.ERESTARTSYS, "sendfile", inFile) + return uintptr(n), nil, handleIOError(t, false, err, kernel.ERESTARTSYS, "sendfile", inFile) } // Splice implements splice(2). @@ -305,6 +310,11 @@ func Tee(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallCo Dup: true, }, nonBlock) + // Tee doesn't change a state of inFD, so it can't lose any data. + if n != 0 { + err = nil + } + // See above; inFile is chosen arbitrarily here. - return uintptr(n), nil, handleIOError(t, n != 0, err, kernel.ERESTARTSYS, "tee", inFile) + return uintptr(n), nil, handleIOError(t, false, err, kernel.ERESTARTSYS, "tee", inFile) } -- cgit v1.2.3