| Message ID | DB3PR10MB683554F488A562C8A89286C2E8AAA@DB3PR10MB6835.EURPRD10.PROD.OUTLOOK.COM (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | Fixes a null pointer dereference in ptp_ioctl | expand |
On Mon, 6 Nov 2023 06:18:29 +0530 Yuran Pereira wrote: > This patch fixes the issue by adding a check for tsevq and > ensuring ptp_ioctl returns with an error if tsevq is null. > > Dashboard link: https://syzkaller.appspot.com/bug?extid=8a78ecea7ac1a2ea26e5 Just Link: > Reported-by: syzbot+8a78ecea7ac1a2ea26e5@syzkaller.appspotmail.com > Fixes: c5a445b1e934 ("ptp: support event queue reader channel masks") > No empty lines between tags. > Signed-off-by: Yuran Pereira <yuran.pereira@hotmail.com> When you repost please make sure you CC everyone get_maintainer (run on the patch file, not the paths) points out. And CC Edward Adam Davis <eadavis@qq.com> since his fixing similar issues.
Hey Jakub, On Tue, Nov 07, 2023 at 10:00:34AM -0800, Jakub Kicinski wrote: > > Just Link: > > > Reported-by: syzbot+8a78ecea7ac1a2ea26e5@syzkaller.appspotmail.com > > Fixes: c5a445b1e934 ("ptp: support event queue reader channel masks") > > > > No empty lines between tags. > Rookie mistake from me. I will pay better attention next time. > > When you repost please make sure you CC everyone get_maintainer > (run on the patch file, not the paths) points out. Interesting, I always run get_maintainer on the modified file will do it on the patch file too from now on. > And CC Edward Adam Davis <eadavis@qq.com> since his fixing similar > issues. Alright, I'll do that. Thank you for the feedback. Yuran
diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c index 282cd7d24077..5b36c34629a0 100644 --- a/drivers/ptp/ptp_chardev.c +++ b/drivers/ptp/ptp_chardev.c @@ -173,6 +173,8 @@ long ptp_ioctl(struct posix_clock_context *pccontext, unsigned int cmd, int enable, err = 0; tsevq = pccontext->private_clkdata; + if (!tsevq) + return -EINVAL; switch (cmd) {
Syzkaller found a null pointer dereference in ptp_ioctl originating from the lack of a null check for tsevq. ``` general protection fault, probably for non-canonical address 0xdffffc000000020b: 0000 [#1] PREEMPT SMP KASAN KASAN: probably user-memory-access in range [0x0000000000001058-0x000000000000105f] CPU: 0 PID: 5053 Comm: syz-executor353 Not tainted 6.6.0-syzkaller-10396-g4652b8e4f3ff #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023 RIP: 0010:ptp_ioctl+0xcb7/0x1d10 drivers/ptp/ptp_chardev.c:476 ... Call Trace: <TASK> posix_clock_ioctl+0xf8/0x160 kernel/time/posix-clock.c:86 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl fs/ioctl.c:857 [inline] __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b ``` This patch fixes the issue by adding a check for tsevq and ensuring ptp_ioctl returns with an error if tsevq is null. Dashboard link: https://syzkaller.appspot.com/bug?extid=8a78ecea7ac1a2ea26e5 Reported-by: syzbot+8a78ecea7ac1a2ea26e5@syzkaller.appspotmail.com Fixes: c5a445b1e934 ("ptp: support event queue reader channel masks") Signed-off-by: Yuran Pereira <yuran.pereira@hotmail.com> --- drivers/ptp/ptp_chardev.c | 2 ++ 1 file changed, 2 insertions(+)