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[PULL 2/5] 9p: local: always return -1 on error in local_unlinkat_common
From: |
Greg Kurz |
Subject: |
[PULL 2/5] 9p: local: always return -1 on error in local_unlinkat_common |
Date: |
Tue, 14 Jan 2020 17:02:32 +0100 |
From: Daniel Henrique Barboza <address@hidden>
local_unlinkat_common() is supposed to always return -1 on error.
This is being done by jumps to the 'err_out' label, which is
a 'return ret' call, and 'ret' is initialized with -1.
Unfortunately there is a condition in which the function will
return 0 on error: in a case where flags == AT_REMOVEDIR, 'ret'
will be 0 when reaching
map_dirfd = openat_dir(...)
And, if map_dirfd == -1 and errno != ENOENT, the existing 'err_out'
jump will execute 'return ret', when ret is still set to zero
at that point.
This patch fixes it by changing all 'err_out' labels by
'return -1' calls, ensuring that the function will always
return -1 on error conditions. 'ret' can be left unintialized
since it's now being used just to store the result of 'unlinkat'
calls.
CC: Greg Kurz <address@hidden>
Signed-off-by: Daniel Henrique Barboza <address@hidden>
[groug: changed prefix in title to be "9p: local:"]
Signed-off-by: Greg Kurz <address@hidden>
---
hw/9pfs/9p-local.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)
diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c
index d0592c3b4504..54e012e5b442 100644
--- a/hw/9pfs/9p-local.c
+++ b/hw/9pfs/9p-local.c
@@ -1076,7 +1076,7 @@ out:
static int local_unlinkat_common(FsContext *ctx, int dirfd, const char *name,
int flags)
{
- int ret = -1;
+ int ret;
if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
int map_dirfd;
@@ -1094,12 +1094,12 @@ static int local_unlinkat_common(FsContext *ctx, int
dirfd, const char *name,
fd = openat_dir(dirfd, name);
if (fd == -1) {
- goto err_out;
+ return -1;
}
ret = unlinkat(fd, VIRTFS_META_DIR, AT_REMOVEDIR);
close_preserve_errno(fd);
if (ret < 0 && errno != ENOENT) {
- goto err_out;
+ return -1;
}
}
map_dirfd = openat_dir(dirfd, VIRTFS_META_DIR);
@@ -1107,16 +1107,14 @@ static int local_unlinkat_common(FsContext *ctx, int
dirfd, const char *name,
ret = unlinkat(map_dirfd, name, 0);
close_preserve_errno(map_dirfd);
if (ret < 0 && errno != ENOENT) {
- goto err_out;
+ return -1;
}
} else if (errno != ENOENT) {
- goto err_out;
+ return -1;
}
}
- ret = unlinkat(dirfd, name, flags);
-err_out:
- return ret;
+ return unlinkat(dirfd, name, flags);
}
static int local_remove(FsContext *ctx, const char *path)
--
2.21.1
- [PULL 0/5] 9p patches 2020-01-14, Greg Kurz, 2020/01/14
- [PULL 2/5] 9p: local: always return -1 on error in local_unlinkat_common,
Greg Kurz <=
- [PULL 1/5] 9pfs: local: Fix possible memory leak in local_link(), Greg Kurz, 2020/01/14
- [PULL 3/5] 9p: init_in_iov_from_pdu can truncate the size, Greg Kurz, 2020/01/14
- [PULL 4/5] virtfs-proxy-helper.c: remove 'err_out' label in setugid(), Greg Kurz, 2020/01/14
- [PULL 5/5] 9pfs/9p.c: remove unneeded labels, Greg Kurz, 2020/01/14
- Re: [PULL 0/5] 9p patches 2020-01-14, Peter Maydell, 2020/01/17