From: Vivek Goyal <vgoyal@redhat.com> To: qemu-devel@nongnu.org Cc: virtio-fs@redhat.com, lhenriques@suse.de, dgilbert@redhat.com, vgoyal@redhat.com, miklos@szeredi.hu Subject: [PATCH v6 3/8] virtiofsd: Fix xattr operations overwriting errno Date: Thu, 17 Jun 2021 14:12:08 -0400 [thread overview] Message-ID: <20210617181213.1177835-4-vgoyal@redhat.com> (raw) In-Reply-To: <20210617181213.1177835-1-vgoyal@redhat.com> 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 <vgoyal@redhat.com> --- 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 49c21fd855..ec91b3c133 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); -- 2.25.4
WARNING: multiple messages have this Message-ID (diff)
From: Vivek Goyal <vgoyal@redhat.com> To: qemu-devel@nongnu.org Cc: virtio-fs@redhat.com, vgoyal@redhat.com, miklos@szeredi.hu Subject: [Virtio-fs] [PATCH v6 3/8] virtiofsd: Fix xattr operations overwriting errno Date: Thu, 17 Jun 2021 14:12:08 -0400 [thread overview] Message-ID: <20210617181213.1177835-4-vgoyal@redhat.com> (raw) In-Reply-To: <20210617181213.1177835-1-vgoyal@redhat.com> 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 <vgoyal@redhat.com> --- 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 49c21fd855..ec91b3c133 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); -- 2.25.4
next prev parent reply other threads:[~2021-06-17 18:14 UTC|newest] Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-06-17 18:12 [PATCH v6 0/8] virtiofsd: Add support to enable/disable posix acls Vivek Goyal 2021-06-17 18:12 ` [Virtio-fs] " Vivek Goyal 2021-06-17 18:12 ` [PATCH v6 1/8] linux-headers: Update linux headers to 5.13.0-rc6 Vivek Goyal 2021-06-17 18:12 ` [Virtio-fs] " Vivek Goyal 2021-06-17 18:12 ` [PATCH v6 2/8] virtiofsd: Fix fuse setxattr() API change issue Vivek Goyal 2021-06-17 18:12 ` [Virtio-fs] " Vivek Goyal 2021-06-17 18:12 ` Vivek Goyal [this message] 2021-06-17 18:12 ` [Virtio-fs] [PATCH v6 3/8] virtiofsd: Fix xattr operations overwriting errno Vivek Goyal 2021-06-17 18:12 ` [PATCH v6 4/8] virtiofsd: Add support for extended setxattr Vivek Goyal 2021-06-17 18:12 ` [Virtio-fs] " Vivek Goyal 2021-06-17 18:12 ` [PATCH v6 5/8] virtiofsd: Add umask to seccom allow list Vivek Goyal 2021-06-17 18:12 ` [Virtio-fs] " Vivek Goyal 2021-06-17 18:12 ` [PATCH v6 6/8] virtiofsd: Add capability to change/restore umask Vivek Goyal 2021-06-17 18:12 ` [Virtio-fs] " Vivek Goyal 2021-06-17 18:12 ` [PATCH v6 7/8] virtiofsd: Switch creds, drop FSETID for system.posix_acl_access xattr Vivek Goyal 2021-06-17 18:12 ` [Virtio-fs] " Vivek Goyal 2021-06-17 18:12 ` [PATCH v6 8/8] virtiofsd: Add an option to enable/disable posix acls Vivek Goyal 2021-06-17 18:12 ` [Virtio-fs] " Vivek Goyal 2021-06-17 18:24 ` [PATCH v6 0/8] virtiofsd: Add support " no-reply 2021-06-17 18:24 ` [Virtio-fs] " no-reply
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