Jiri Olsa dc1892c4bc tty,vcs: lseek/VC-release race fix ... there's a race between vcs's lseek handler and VC release. The lseek handler does not hold console_lock and touches VC's size info. If during this the VC got released, there's an access violation. Following program triggers the issue for me: [SNIP] #define _BSD_SOURCE #include <stdio.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <sys/ioctl.h> #include <linux/vt.h> #include <unistd.h> #include <errno.h> static int run_seek(void) { while(1) { int fd; fd = open("./vcs30", O_RDWR); while(lseek(fd, 0, 0) != -1); close(fd); } } static int open_ioctl_tty(void) { return open("/dev/tty1", O_RDWR); } static int do_ioctl(int fd, int req, int i) { return ioctl(fd, req, i); } #define INIT(i) do_ioctl(ioctl_fd, VT_ACTIVATE, i) #define SHUT(i) do_ioctl(ioctl_fd, VT_DISALLOCATE, i) int main(int argc, char **argv) { int ioctl_fd = open_ioctl_tty(); if (ioctl < 0) { perror("open tty1 failed\n"); return -1; } if ((-1 == mknod("vcs30", S_IFCHR|0666, makedev(7, 30))) && (errno != EEXIST)) { printf("errno %d\n", errno); perror("failed to create vcs30"); return -1; } do_ioctl(ioctl_fd, VT_LOCKSWITCH, 0); if (!fork()) run_seek(); while(1) { INIT(30); SHUT(30); } return 0; } [SNIP] Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>		2011-02-17 11:13:19 -08:00
..
hvc	hvc: add Blackfin JTAG console support	2011-02-17 11:12:40 -08:00
serial	serial: pch_uart: revert Kconfig for non-DMA mode	2011-02-03 14:19:33 -08:00
vt	tty,vcs: lseek/VC-release race fix	2011-02-17 11:13:19 -08:00
Makefile
n_gsm.c
n_hdlc.c
n_r3964.c
n_tty.c
pty.c
sysrq.c
tty_audit.c
tty_buffer.c
tty_io.c
tty_ioctl.c
tty_ldisc.c	tty_ldisc: don't use flush_scheduled_work()	2011-02-03 14:12:25 -08:00
tty_mutex.c
tty_port.c