From a3f844da91f0c01209a5d778a5af57fabe245332 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Fri, 16 Jul 2021 22:31:26 -0400 Subject: [PATCH] libe2p: use stat to prevent calling EXT2_IOC_[GS]ETFLAGS on devices Some devices can react badly to the EXT2_IOC_[GS]ETFLAGS ioctls, since ioctl codes are not guaranteed to be unique across different device drivers and file systems. Addresses-Debian-Bug: #986332 Signed-off-by: Theodore Ts'o --- lib/e2p/fgetflags.c | 12 ++++++++++++ lib/e2p/fsetflags.c | 12 ++++++++++++ 2 files changed, 24 insertions(+) diff --git a/lib/e2p/fgetflags.c b/lib/e2p/fgetflags.c index 93e130c..24a7166 100644 --- a/lib/e2p/fgetflags.c +++ b/lib/e2p/fgetflags.c @@ -79,14 +79,26 @@ int fgetflags (const char * name, unsigned long * flags) *flags = f; return (save_errno); #elif HAVE_EXT2_IOCTLS + struct stat buf; int fd, r, f, save_errno = 0; + if (!stat(name, &buf) && + !S_ISREG(buf.st_mode) && !S_ISDIR(buf.st_mode)) { + errno = EOPNOTSUPP; + return -1; + } fd = open(name, OPEN_FLAGS); if (fd == -1) { if (errno == ELOOP || errno == ENXIO) errno = EOPNOTSUPP; return -1; } + if (!fstat(fd, &buf) && + !S_ISREG(buf.st_mode) && !S_ISDIR(buf.st_mode)) { + close(fd); + errno = EOPNOTSUPP; + return -1; + } r = ioctl(fd, EXT2_IOC_GETFLAGS, &f); if (r == -1) { if (errno == ENOTTY) diff --git a/lib/e2p/fsetflags.c b/lib/e2p/fsetflags.c index 6455e38..d865d24 100644 --- a/lib/e2p/fsetflags.c +++ b/lib/e2p/fsetflags.c @@ -80,14 +80,26 @@ int fsetflags (const char * name, unsigned long flags) int f = (int) flags; return syscall(SYS_fsctl, name, EXT2_IOC_SETFLAGS, &f, 0); #elif HAVE_EXT2_IOCTLS + struct stat buf; int fd, r, f, save_errno = 0; + if (!stat(name, &buf) && + !S_ISREG(buf.st_mode) && !S_ISDIR(buf.st_mode)) { + errno = EOPNOTSUPP; + return -1; + } fd = open(name, OPEN_FLAGS); if (fd == -1) { if (errno == ELOOP || errno == ENXIO) errno = EOPNOTSUPP; return -1; } + if (!fstat(fd, &buf) && + !S_ISREG(buf.st_mode) && !S_ISDIR(buf.st_mode)) { + close(fd); + errno = EOPNOTSUPP; + return -1; + } f = (int) flags; r = ioctl(fd, EXT2_IOC_SETFLAGS, &f); if (r == -1) { -- 1.8.3.1