d48e81f0c
Denis Vlasenko
2008-07-06
Subject
mdev: do not follow symlinks in /sys (as was intended prior to rev 18811). If this breaks things, please document why! mdev,init: use shared code for fd sanitization
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Build Log
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Commit Diff GitHub →
init/init.c+1 -14
| @@ -221,20 +221,7 @@ static void console_init(void) | |
| } else { | |
| /* Make sure fd 0,1,2 are not closed | |
| * (so that they won't be used by future opens) */ | |
| - | |
| - | /* bb_sanitize_stdio(); - WRONG. |
| - | * It fails if "/dev/null" doesnt exist, and for init |
| - | * this is a real possibility! Open code it instead. */ |
| - | |
| - | int fd = open(bb_dev_null, O_RDWR); |
| - | if (fd < 0) { |
| - | /* Give me _ANY_ open descriptor! */ |
| - | fd = xopen("/", O_RDONLY); /* we don't believe this can fail */ |
| - | } |
| - | while ((unsigned)fd < 2) |
| - | fd = dup(fd); |
| - | if (fd > 2) |
| - | close(fd); |
| + | bb_sanitize_stdio(); |
| } | |
| s = getenv("TERM"); | |
libbb/vfork_daemon_rexec.c+8 -1
| @@ -265,7 +265,14 @@ void FAST_FUNC bb_daemonize_or_rexec(int flags, char **argv) | |
| close(2); | |
| } | |
| - | fd = xopen(bb_dev_null, O_RDWR); |
| + | fd = open(bb_dev_null, O_RDWR); |
| + | if (fd < 0) { |
| + | /* NB: we can be called as bb_sanitize_stdio() from init |
| + | * or mdev, and there /dev/null may legitimately not (yet) exist! |
| + | * Do not use xopen above, but obtain _ANY_ open descriptor, |
| + | * even bogus one as below. */ |
| + | fd = xopen("/", O_RDONLY); /* don't believe this can fail */ |
| + | } |
| while ((unsigned)fd < 2) | |
| fd = dup(fd); /* have 0,1,2 open at least to /dev/null */ | |
util-linux/mdev.c+12 -5
| @@ -19,7 +19,8 @@ struct globals { | |
| #define root_major (G.root_major) | |
| #define root_minor (G.root_minor) | |
| - | #define MAX_SYSFS_DEPTH 3 /* prevent infinite loops in /sys symlinks */ |
| + | /* Prevent infinite loops in /sys symlinks */ |
| + | #define MAX_SYSFS_DEPTH 3 |
| /* We use additional 64+ bytes in make_device() */ | |
| #define SCRATCH_SIZE 80 | |
| @@ -392,11 +393,17 @@ int mdev_main(int argc, char **argv) | |
| char *env_path; | |
| RESERVE_CONFIG_BUFFER(temp, PATH_MAX + SCRATCH_SIZE); | |
| - | #ifdef YOU_WANT_TO_DEBUG_HOTPLUG_EVENTS |
| + | /* We can be called as hotplug helper */ |
| /* Kernel cannot provide suitable stdio fds for us, do it ourself */ | |
| + | #if 1 |
| + | bb_sanitize_stdio(); |
| + | #else |
| + | /* Debug code */ |
| /* Replace LOGFILE by other file or device name if you need */ | |
| #define LOGFILE "/dev/console" | |
| - | xmove_fd(xopen("/dev/null", O_RDONLY), STDIN_FILENO); |
| + | /* Just making sure fd 0 is not closed, |
| + | * we don't really intend to read from it */ |
| + | xmove_fd(xopen("/", O_RDONLY), STDIN_FILENO); |
| xmove_fd(xopen(LOGFILE, O_WRONLY|O_APPEND), STDOUT_FILENO); | |
| xmove_fd(xopen(LOGFILE, O_WRONLY|O_APPEND), STDERR_FILENO); | |
| #endif | |
| @@ -414,11 +421,11 @@ int mdev_main(int argc, char **argv) | |
| root_minor = minor(st.st_dev); | |
| recursive_action("/sys/block", | |
| - | ACTION_RECURSE | ACTION_FOLLOWLINKS, |
| + | ACTION_RECURSE /* no ACTION_FOLLOWLINKS! */, |
| fileAction, dirAction, temp, 0); | |
| recursive_action("/sys/class", | |
| - | ACTION_RECURSE | ACTION_FOLLOWLINKS, |
| + | ACTION_RECURSE /* no ACTION_FOLLOWLINKS! */, |
| fileAction, dirAction, temp, 0); | |
| } else { | |