From 5290fb625d1bf692306ee958efc67c8620866f67 Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Tue, 22 Jun 2021 11:08:47 -0400 Subject: virtiofsd: Fix xattr operations overwriting errno getxattr/setxattr/removexattr/listxattr operations handle regualar and non-regular files differently. For the case of non-regular files we do fchdir(/proc/self/fd) and the xattr operation and then revert back to original working directory. After this we are saving errno and that's buggy because fchdir() will overwrite the errno. FCHDIR_NOFAIL(lo->proc_self_fd); ret = getxattr(procname, name, value, size); FCHDIR_NOFAIL(lo->root.fd); if (ret == -1) saverr = errno In above example, if getxattr() failed, we will still return 0 to caller as errno must have been written by FCHDIR_NOFAIL(lo->root.fd) call. Fix all such instances and capture "errno" early and save in "saverr" variable. Signed-off-by: Vivek Goyal Message-Id: <20210622150852.1507204-3-vgoyal@redhat.com> Reviewed-by: Dr. David Alan Gilbert Reviewed-by: Greg Kurz Signed-off-by: Dr. David Alan Gilbert --- tools/virtiofsd/passthrough_ll.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c index 9858e96..ccbda98 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -2791,15 +2791,17 @@ static void lo_getxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, goto out_err; } ret = fgetxattr(fd, name, value, size); + saverr = ret == -1 ? errno : 0; } else { /* fchdir should not fail here */ FCHDIR_NOFAIL(lo->proc_self_fd); ret = getxattr(procname, name, value, size); + saverr = ret == -1 ? errno : 0; FCHDIR_NOFAIL(lo->root.fd); } if (ret == -1) { - goto out_err; + goto out; } if (size) { saverr = 0; @@ -2864,15 +2866,17 @@ static void lo_listxattr(fuse_req_t req, fuse_ino_t ino, size_t size) goto out_err; } ret = flistxattr(fd, value, size); + saverr = ret == -1 ? errno : 0; } else { /* fchdir should not fail here */ FCHDIR_NOFAIL(lo->proc_self_fd); ret = listxattr(procname, value, size); + saverr = ret == -1 ? errno : 0; FCHDIR_NOFAIL(lo->root.fd); } if (ret == -1) { - goto out_err; + goto out; } if (size) { saverr = 0; @@ -2998,15 +3002,15 @@ static void lo_setxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, goto out; } ret = fsetxattr(fd, name, value, size, flags); + saverr = ret == -1 ? errno : 0; } else { /* fchdir should not fail here */ FCHDIR_NOFAIL(lo->proc_self_fd); ret = setxattr(procname, name, value, size, flags); + saverr = ret == -1 ? errno : 0; FCHDIR_NOFAIL(lo->root.fd); } - saverr = ret == -1 ? errno : 0; - out: if (fd >= 0) { close(fd); @@ -3064,15 +3068,15 @@ static void lo_removexattr(fuse_req_t req, fuse_ino_t ino, const char *in_name) goto out; } ret = fremovexattr(fd, name); + saverr = ret == -1 ? errno : 0; } else { /* fchdir should not fail here */ FCHDIR_NOFAIL(lo->proc_self_fd); ret = removexattr(procname, name); + saverr = ret == -1 ? errno : 0; FCHDIR_NOFAIL(lo->root.fd); } - saverr = ret == -1 ? errno : 0; - out: if (fd >= 0) { close(fd); -- cgit v1.1