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author | Szabolcs Nagy <nsz@port70.net> | 2016-08-20 21:04:31 +0200 |
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committer | Rich Felker <dalias@aerifal.cx> | 2016-08-30 15:59:50 -0400 |
commit | 0a950dcf15bb9f7274c804dca490e9e20e475f3e (patch) | |
tree | 593648d221561d6f98d25b6fadf3949580f92eda | |
parent | 2b41959b59e3dfd70cb4b592ffb2d97b47584aaa (diff) | |
download | musl-0a950dcf15bb9f7274c804dca490e9e20e475f3e.tar.gz musl-0a950dcf15bb9f7274c804dca490e9e20e475f3e.tar.bz2 musl-0a950dcf15bb9f7274c804dca490e9e20e475f3e.tar.xz musl-0a950dcf15bb9f7274c804dca490e9e20e475f3e.zip |
verify that ttyname refers to the same file as the fd
linux containers use separate mount namespace so the /proc
symlink might not point to the right device if the fd was
opened in the parent namespace, in this case return ENOENT.
-rw-r--r-- | src/unistd/ttyname_r.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/src/unistd/ttyname_r.c b/src/unistd/ttyname_r.c index 8bac7b2f..a38ba4f2 100644 --- a/src/unistd/ttyname_r.c +++ b/src/unistd/ttyname_r.c @@ -1,10 +1,12 @@ #include <unistd.h> #include <errno.h> +#include <sys/stat.h> void __procfdname(char *, unsigned); int ttyname_r(int fd, char *name, size_t size) { + struct stat st1, st2; char procname[sizeof "/proc/self/fd/" + 3*sizeof(int) + 2]; ssize_t l; @@ -15,8 +17,13 @@ int ttyname_r(int fd, char *name, size_t size) if (l < 0) return errno; else if (l == size) return ERANGE; - else { - name[l] = 0; - return 0; - } + + name[l] = 0; + + if (stat(name, &st1) || fstat(fd, &st2)) + return errno; + if (st1.st_dev != st2.st_dev || st1.st_ino != st2.st_ino) + return ENOENT; + + return 0; } |