From 4fa4ce7107c6ec432f185307158c5df91ce54308 Mon Sep 17 00:00:00 2001 From: Chen Gang Date: Sun, 2 Mar 2014 01:36:19 +0800 Subject: hw/9pfs: use g_strdup_printf() instead of PATH_MAX limitation When path is truncated by PATH_MAX limitation, it causes QEMU to access incorrect file. So use original full path instead of PATH_MAX within 9pfs (need check/process ENOMEM for related memory allocation). The related test: - Environments (for qemu-devel): - Host is under fedora17 desktop with ext4fs: qemu-system-x86_64 -hda test.img -m 1024 \ -net nic,vlan=4,model=virtio,macaddr=00:16:35:AF:94:04 \ -net tap,vlan=4,ifname=tap4,script=no,downscript=no \ -device virtio-9p-pci,id=fs0,fsdev=fsdev0,mount_tag=hostshare \ -fsdev local,security_model=passthrough,id=fsdev0,\ path=/upstream/vm/data/share/1234567890abcdefghijklmnopqrstuvwxyz\ ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890acdefghijklmnopqrstuvwxyz\ ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890/111111111111111111111111111\ 1111111111111111111111111111111111111111111111111111222222222222\ 2222222222222222222222222222222222222222222222222222222222222222\ 2222222222222222222222222222222222233333333333333333333333333333\ 3333333333333333333333333333333333 - Guest is ubuntu12 server with 9pfs. mount -t 9p -o trans=virtio,version=9p2000.L hostshare /share - Limitations: full path limitation is PATH_MAX (4096B include nul) under Linux. file/dir node name maximized length is 256 (include nul) under ext4. - Special test: Under host, modify the file: "/upstream/vm/data/share/1234567890abcdefg\ hijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890acdefghijklmno\ pqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890/111111111111111111111\ 111111111111111111111111111111111111111111111111111111111122222222222\ 222222222222222222222222222222222222222222222222222222222222222222222\ 222222222222222222222222222222233333333333333333333333333333333333333\ 3333333333333333333333333/4444444444444444444444444444444444444444444\ 444444444444444444444444444444444444444444444444444444444444444444444\ 444444444444444444444444444444444444444444444444444444444444444444444\ 444444444444444444444444444444444444444/55555555555555555555555555555\ 555555555555555555555555555555555555555555555555555555555555555555555\ 555555555555555555555555555555555555555555555555555555555555555555555\ 555555555555555555555555555555555555555555555555555555555555555555555\ 55555555/666666666666666666666666666666666666666666666666666666666666\ 666666666666666666666666666666666666666666666666666666666666666666666\ 666666666666666666666666666666666666666666666666666666666666666666666\ 666666666666666666666/77777777777777777777777777777777777777777777777\ 777777777777777777777777777777777777777777777777777777777777777777777\ 777777777777777777777777777777777777777777777777777777777777777777777\ 77777777777777777777777777777777777777777777777777777777777/888888888\ 888888888888888888888888888888888888888888888888888888888888888888888\ 888888888888888888888888888888888888888888888888888888888888888888888\ 888888888888888888888888888888888888888888888888888888888888888888888\ 888888888/99999999999999999999999999999999999999999999999999999999999\ 999999999999999999999999999999999999999999999999999999999999999999999\ 999999999999999999999999999999999999999999999999999999999999999999999\ 99999999999999999999999999999999999999999/000000000000000000000000000\ 000000000000000000000000000000000000000000000000000000000000000000000\ 000000000000000000000000000000000000000000000000000000000000000000000\ 000000000000000000000000000000000000000000000000/aaaaaaaaaaaaaaaaaaaa\ aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\ aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\ aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/bbbbbbbbbbbbbbbbbbbbbbb\ bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb\ bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb\ bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb/ccccccccc\ ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc\ ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc\ ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc\ cccccccccc/dddddddddddddddddddddddddddddddddddddddddddddddddddddddddd\ ddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd\ ddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd\ dddddddddddddddddddddd/eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee\ eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee\ eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee\ eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee/fffffffffffffff\ fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff\ fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff\ ffffffffffffffffffffffffffffffffffffffffffffffffffffffffff/gggggggggg\ ggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg\ ggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg\ ggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg\ ggggggggggggggggggggggg/iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\ iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\ iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\ iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii/jjjjjjjjjjjjj\ jjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj\ jjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj/ppppppppppppppppppppp\ ppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppp\ ppppppppppppppppppppppppppppppppppppppp/test1234567890file.log" (need enter dir firstly, then modify file, or can not open it). Under guest, still allow modify "test1234567890file.log" (will generate "test123456" file with contents). After apply this patch, can not open "test1234567890file.log" under guest (permission denied). - Common test: All are still OK after apply this path. "mkdir -p", "create/open file/dir", "modify file/dir", "rm file/dir". change various mount point paths under host and/or guest. Signed-off-by: Chen Gang Signed-off-by: Aneesh Kumar K.V --- hw/9pfs/virtio-9p-xattr.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'hw/9pfs/virtio-9p-xattr.c') diff --git a/hw/9pfs/virtio-9p-xattr.c b/hw/9pfs/virtio-9p-xattr.c index 3fae557a84..07183887c5 100644 --- a/hw/9pfs/virtio-9p-xattr.c +++ b/hw/9pfs/virtio-9p-xattr.c @@ -67,21 +67,24 @@ ssize_t v9fs_list_xattr(FsContext *ctx, const char *path, void *value, size_t vsize) { ssize_t size = 0; - char buffer[PATH_MAX]; + char *buffer; void *ovalue = value; XattrOperations *xops; char *orig_value, *orig_value_start; ssize_t xattr_len, parsed_len = 0, attr_len; /* Get the actual len */ - xattr_len = llistxattr(rpath(ctx, path, buffer), value, 0); + buffer = rpath(ctx, path); + xattr_len = llistxattr(buffer, value, 0); if (xattr_len <= 0) { + g_free(buffer); return xattr_len; } /* Now fetch the xattr and find the actual size */ orig_value = g_malloc(xattr_len); - xattr_len = llistxattr(rpath(ctx, path, buffer), orig_value, xattr_len); + xattr_len = llistxattr(buffer, orig_value, xattr_len); + g_free(buffer); /* store the orig pointer */ orig_value_start = orig_value; -- cgit v1.2.1