| Message ID | 20231106011926.2928881-1-lizhi.xu@windriver.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | ptp: fix null ptr deref in ptp_ioctrl | expand |
On Mon, 06 Nov, 2023 09:19:26 +0800 Lizhi Xu <lizhi.xu@windriver.com> wrote: <snip> > > It can be confirmed that after the execution of "read (3, 0x20000080, 90)", > ptp_release() will be called to release the queue and set > pccontext->private_clkdata = NULL at the same time, this is unreasonable and > incorrect. The queue is not the memory requested in ptp_read() and should not > be released in ptp_read(). > > Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com> > --- > drivers/ptp/ptp_chardev.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c > index 282cd7d24077..27c1ef493617 100644 > --- a/drivers/ptp/ptp_chardev.c > +++ b/drivers/ptp/ptp_chardev.c > @@ -585,7 +585,5 @@ ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags, > free_event: > kfree(event); > exit: > - if (result < 0) > - ptp_release(pccontext); > return result; > } There is already an ongoing review for a patch submission that covers this. https://lore.kernel.org/netdev/tencent_856E1C97CCE9E2ED66CC087B526CD42ED50A@qq.com/ -- Thanks, Rahul Rameshbabu
diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c index 282cd7d24077..27c1ef493617 100644 --- a/drivers/ptp/ptp_chardev.c +++ b/drivers/ptp/ptp_chardev.c @@ -585,7 +585,5 @@ ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags, free_event: kfree(event); exit: - if (result < 0) - ptp_release(pccontext); return result; }
In the logs recorded in the strace log, https://syzkaller.appspot.com/text?tag=CrashLog&x=11aa125f680000 ... openat(AT_FDCWD, "/dev/ptp0", O_RDONLY) = 3 read(3, 0x20000080, 90) = -1 EINVAL (Invalid argument) 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 Code: 81 fe 13 3d 00 00 0f 85 9c 02 00 00 e8 c2 83 23 fa 49 8d bc 24 58 10 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 dc 0e 00 00 49 8b bc 24 58 10 00 00 ba 00 01 00 RSP: 0018:ffffc90003a37ba0 EFLAGS: 00010212 RAX: dffffc0000000000 RBX: ffff88814a78a000 RCX: ffffffff8764f81f RDX: 000000000000020b RSI: ffffffff8765028e RDI: 0000000000001058 RBP: ffffc90003a37ec0 R08: 0000000000000005 R09: ffffc90003a37c40 R10: 0000000000003d13 R11: 0000000000000000 R12: 0000000000000000 R13: ffffc90003a37c80 R14: 0000000000003d13 R15: ffffffff92ac78e8 FS: 00005555569a9380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000040 CR3: 0000000076e09000 CR4: 0000000000350ef0 Call Trace: <TASK> ? show_regs+0x8f/0xa0 ? die_addr+0x4f/0xd0 ? exc_general_protection+0x154/0x230 ? asm_exc_general_protection+0x26/0x30 ? ptp_ioctl+0x22f/0x1d10 ? ptp_ioctl+0xc9e/0x1d10 ? ptp_ioctl+0xcb7/0x1d10 ? ptp_release+0x2b0/0x2b0 ? lockdep_hardirqs_on_prepare+0x410/0x410 ? lock_sync+0x190/0x190 ? find_held_lock+0x2d/0x110 ? ptp_release+0x2b0/0x2b0 posix_clock_ioctl+0xf8/0x160 ... It can be confirmed that after the execution of "read (3, 0x20000080, 90)", ptp_release() will be called to release the queue and set pccontext->private_clkdata = NULL at the same time, this is unreasonable and incorrect. The queue is not the memory requested in ptp_read() and should not be released in ptp_read(). Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com> --- drivers/ptp/ptp_chardev.c | 2 -- 1 file changed, 2 deletions(-)