On Tue, 21 May 2024 17:31:29 +0200, Greg Kroah-Hartman wrote:
> Description
> ===========
>
> In the Linux kernel, the following vulnerability has been resolved:
>
> samples/bpf: syscall_tp_user: Fix array out-of-bound access
>
> Commit 06744f24696e ("samples/bpf: Add openat2() enter/exit tracepoint
> to syscall_tp sample") added two more eBPF programs to support the
> openat2() syscall. However, it did not increase the size of the array
> that holds the corresponding bpf_links. This leads to an out-of-bound
> access on that array in the bpf_object__for_each_program loop and could
> corrupt other variables on the stack. On our testing QEMU, it corrupts
> the map1_fds array and causes the sample to fail:
>
> # ./syscall_tp
> prog #0: map ids 4 5
> verify map:4 val: 5
> map_lookup failed: Bad file descriptor
>
> Dynamically allocate the array based on the number of programs reported
> by libbpf to prevent similar inconsistencies in the future
>
> The Linux kernel CVE team has assigned CVE-2023-52793 to this issue.
I would like to dispute this CVE.
Files in samples/bpf are meant to serve as an example and not code that
are directly used at run-time, hence I believe this bug does not have
security implication.
--
Shung-Hsi Yu
> ...
On Fri, May 24, 2024 at 11:58:54AM +0800, Shung-Hsi Yu wrote:
> On Tue, 21 May 2024 17:31:29 +0200, Greg Kroah-Hartman wrote:
> > Description
> > ===========
> >
> > In the Linux kernel, the following vulnerability has been resolved:
> >
> > samples/bpf: syscall_tp_user: Fix array out-of-bound access
> >
> > Commit 06744f24696e ("samples/bpf: Add openat2() enter/exit tracepoint
> > to syscall_tp sample") added two more eBPF programs to support the
> > openat2() syscall. However, it did not increase the size of the array
> > that holds the corresponding bpf_links. This leads to an out-of-bound
> > access on that array in the bpf_object__for_each_program loop and could
> > corrupt other variables on the stack. On our testing QEMU, it corrupts
> > the map1_fds array and causes the sample to fail:
> >
> > # ./syscall_tp
> > prog #0: map ids 4 5
> > verify map:4 val: 5
> > map_lookup failed: Bad file descriptor
> >
> > Dynamically allocate the array based on the number of programs reported
> > by libbpf to prevent similar inconsistencies in the future
> >
> > The Linux kernel CVE team has assigned CVE-2023-52793 to this issue.
>
> I would like to dispute this CVE.
>
> Files in samples/bpf are meant to serve as an example and not code that
> are directly used at run-time, hence I believe this bug does not have
> security implication.
You are right, sorry about that, now rejected. Thanks for the review!
greg k-h