当我尝试以特定用户 ( ) 身份访问某个目录中的任何文件时，遇到一个非常奇怪的权限问题adventho。这几个月来一直运行良好，我最近才注意到我收到了这些错误，并且有一段时间我没有更改系统中的任何内容。这是当用户尝试访问任何文件时会发生的情况：
# su adventho
adventho@snail:/root
$ stat /home/adventho/public_html/hotelimg/187-1-1403380618.jpg
stat: cannot stat `/home/adventho/public_html/hotelimg/187-1-1403380618.jpg': Permission denied
不过我可以以root身份很好地访问它：
root@snail:~# stat /home/adventho/public_html/hotelimg/187-1-1403380618.jpg
File: `/home/adventho/public_html/hotelimg/187-1-1403380618.jpg'
Size: 528535 Blocks: 1040 IO Block: 4096 regular file
Device: 906h/2310d Inode: 918000 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 1030/adventho) Gid: ( 1008/adventho)
Access: 2014-12-15 17:23:44.318374774 -0500
Modify: 2014-06-21 15:56:58.000000000 -0400
Change: 2014-10-23 16:44:57.502377342 -0400
Birth: -
事实上，ls -la在目录上执行操作会产生一堆“？”在输出中，即使对于.和..：
d????????? ? ? ? ? ? .
d????????? ? ? ? ? ? ..
-????????? ? ? ? ? ? 106-1-1239840962_800_600_180_135.jpg
-????????? ? ? ? ? ? 106-1-1239840962_800_600_240_180.jpg
-????????? ? ? ? ? ? 106-1-1239840962_800_600.jpg
-????????? ? ? ? ? ? 106-2-1239840963_800_600_180_135.jpg
-????????? ? ? ? ? ? 106-2-1239840963_800_600_240_180.jpg
-????????? ? ? ? ? ? 106-2-1239840963_800_600.jpg
-????????? ? ? ? ? ? 106-3-1239840964_800_600_180_135.jpg
-????????? ? ? ? ? ? 106-3-1239840964_800_600_240_180.jpg
-????????? ? ? ? ? ? 106-3-1239840964_800_600.jpg
但如果我这样做，ls -ld hotelimg/我会得到一个输出：
drw-rw-r-- 2 adventho www-data 69632 Dec 15 17:23 hotelimg/
如果我添加任何事物斜线之后，我的权限被拒绝：
$ ls -ld hotelimg/../index.php
ls: cannot access hotelimg/../some_existent_file: Permission denied
$ ls -ld hotelimg/.
ls: cannot access hotelimg/.: Permission denied
$ ls -ld hotelimg/../
ls: cannot access hotelimg/../: Permission denied
我试着做一个strace，ls这是输出：
$ strace ls /home/adventho/public_html/hotelimg/187-1-1403380618.jpg
execve("/bin/ls", ["ls", "/home/adventho/public_html/hotel"...], [/* 13 vars */]) = 0
brk(0) = 0x1db6000
access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f931a148000
access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=26612, ...}) = 0
mmap(NULL, 26612, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f931a141000
close(3) = 0
access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libselinux.so.1", O_RDONLY) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\260f\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=126232, ...}) = 0
mmap(NULL, 2226160, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f9319d0b000
mprotect(0x7f9319d29000, 2093056, PROT_NONE) = 0
mmap(0x7f9319f28000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1d000) = 0x7f9319f28000
mmap(0x7f9319f2a000, 2032, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f9319f2a000
close(3) = 0
access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/librt.so.1", O_RDONLY) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\220!\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=31744, ...}) = 0
mmap(NULL, 2128856, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f9319b03000
mprotect(0x7f9319b0a000, 2093056, PROT_NONE) = 0
mmap(0x7f9319d09000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x6000) = 0x7f9319d09000
close(3) = 0
access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libacl.so.1", O_RDONLY) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0`\"\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=35320, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f931a140000
mmap(NULL, 2130560, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f93198fa000
mprotect(0x7f9319902000, 2093056, PROT_NONE) = 0
mmap(0x7f9319b01000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x7000) = 0x7f9319b01000
close(3) = 0
access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\300\357\1\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1603600, ...}) = 0
mmap(NULL, 3717176, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f931956e000
mprotect(0x7f93196f0000, 2097152, PROT_NONE) = 0
mmap(0x7f93198f0000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x182000) = 0x7f93198f0000
mmap(0x7f93198f5000, 18488, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f93198f5000
close(3) = 0
access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libdl.so.2", O_RDONLY) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\340\r\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=14768, ...}) = 0
mmap(NULL, 2109696, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f931936a000
mprotect(0x7f931936c000, 2097152, PROT_NONE) = 0
mmap(0x7f931956c000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x2000) = 0x7f931956c000
close(3) = 0
access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libpthread.so.0", O_RDONLY) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0@\\\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=131107, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f931a13f000
mmap(NULL, 2208672, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f931914e000
mprotect(0x7f9319165000, 2093056, PROT_NONE) = 0
mmap(0x7f9319364000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x16000) = 0x7f9319364000
mmap(0x7f9319366000, 13216, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f9319366000
close(3) = 0
access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libattr.so.1", O_RDONLY) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0000\25\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=18672, ...}) = 0
mmap(NULL, 2113880, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f9318f49000
mprotect(0x7f9318f4d000, 2093056, PROT_NONE) = 0
mmap(0x7f931914c000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x3000) = 0x7f931914c000
close(3) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f931a13e000
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f931a13c000
arch_prctl(ARCH_SET_FS, 0x7f931a13c7a0) = 0
mprotect(0x7f931914c000, 4096, PROT_READ) = 0
mprotect(0x7f9319364000, 4096, PROT_READ) = 0
mprotect(0x7f931956c000, 4096, PROT_READ) = 0
mprotect(0x7f93198f0000, 16384, PROT_READ) = 0
mprotect(0x7f9319b01000, 4096, PROT_READ) = 0
mprotect(0x7f9319d09000, 4096, PROT_READ) = 0
mprotect(0x7f9319f28000, 4096, PROT_READ) = 0
mprotect(0x61a000, 4096, PROT_READ) = 0
mprotect(0x7f931a14a000, 4096, PROT_READ) = 0
munmap(0x7f931a141000, 26612) = 0
set_tid_address(0x7f931a13ca70) = 22762
set_robust_list(0x7f931a13ca80, 0x18) = 0
futex(0x7fff8335414c, FUTEX_WAIT_BITSET_PRIVATE|FUTEX_CLOCK_REALTIME, 1, NULL, 7f931a13c7a0) = -1 EAGAIN (Resource temporarily unavailable)
rt_sigaction(SIGRTMIN, {0x7f9319153ad0, [], SA_RESTORER|SA_SIGINFO, 0x7f931915d0a0}, NULL, 8) = 0
rt_sigaction(SIGRT_1, {0x7f9319153b60, [], SA_RESTORER|SA_RESTART|SA_SIGINFO, 0x7f931915d0a0}, NULL, 8) = 0
rt_sigprocmask(SIG_UNBLOCK, [RTMIN RT_1], NULL, 8) = 0
getrlimit(RLIMIT_STACK, {rlim_cur=8192*1024, rlim_max=RLIM_INFINITY}) = 0
statfs("/sys/fs/selinux", 0x7fff833540a0) = -1 ENOENT (No such file or directory)
statfs("/selinux", {f_type="EXT2_SUPER_MAGIC", f_bsize=4096, f_blocks=1440781, f_bfree=1145015, f_bavail=1071826, f_files=366480, f_ffree=337819, f_fsid={-205162666, 1274914527}, f_namelen=255, f_frsize=4096}) = 0
brk(0) = 0x1db6000
brk(0x1dd7000) = 0x1dd7000
open("/proc/filesystems", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0444, st_size=0, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f931a147000
read(3, "nodev\tsysfs\nnodev\trootfs\nnodev\tb"..., 1024) = 385
read(3, "", 1024) = 0
close(3) = 0
munmap(0x7f931a147000, 4096) = 0
open("/usr/lib/locale/locale-archive", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=110939968, ...}) = 0
mmap(NULL, 110939968, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f931257c000
close(3) = 0
ioctl(1, SNDCTL_TMR_TIMEBASE or TCGETS, {B38400 opost isig icanon echo ...}) = 0
ioctl(1, TIOCGWINSZ, {ws_row=39, ws_col=153, ws_xpixel=0, ws_ypixel=0}) = 0
stat("/home/adventho/public_html/hotelimg/187-1-1403380618.jpg", 0x1db70d0) = -1 EACCES (Permission denied)
open("/usr/share/locale/locale.alias", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=2570, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f931a147000
read(3, "# Locale name alias data base.\n#"..., 4096) = 2570
read(3, "", 4096) = 0
close(3) = 0
munmap(0x7f931a147000, 4096) = 0
open("/usr/share/locale/en_US.UTF-8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/en_US.utf8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/en_US/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/en.UTF-8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/en.utf8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/en/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
write(2, "ls: ", 4ls: ) = 4
write(2, "cannot access /home/adventho/pub"..., 70cannot access /home/adventho/public_html/hotelimg/187-1-1403380618.jpg) = 70
open("/usr/share/locale/en_US.UTF-8/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/en_US.utf8/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/en_US/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/en.UTF-8/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/en.utf8/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/en/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
write(2, ": Permission denied", 19: Permission denied) = 19
write(2, "\n", 1
) = 1
close(1) = 0
close(2) = 0
exit_group(2) = ?
我注意到它提到了selinux，但它没有安装。为了再次确认，我安装了policycoreutils（安装了 55 个其他软件包）并执行sestatus，输出被“禁用”。服务器上安装的所有内容（唯一的例外是 lfd/csf）都来自存储库。
我很困惑是什么导致了这些权限被拒绝的错误。
答案1
目录的读取权限仅允许您列出其内容。为了真正能够访问内容，您需要执行权限。相反，仅具有执行权限将允许您访问内容，但不能列出它们。看执行与读取位。 Linux 中的目录权限如何工作？
答案2
目录有两种操作方式。第一个是读取或浏览目录，也称为运行LS命令，另一个是执行目录。需要执行才能打开请求目录中的文件或目录。执行是对请求的名称进行 inode 查找，并且您不必能够读取该目录。
在你的情况下目录酒店管理缺少执行权限。添加那些与'chmod +x hotelimg'应该解决权限问题。