Hi Bruce, I have checked linux-yocto -stable updates , not seen these changes in 5.10.y. could please point me the commit which you pushed to the 5.10.y
Regards, Archana ________________________________ From: Bruce Ashfield <[email protected]> Sent: Thursday, July 18, 2024 18:54 To: Polampalli, Archana <[email protected]> Cc: [email protected] <[email protected]> Subject: Re: [linux-yocto][v5.10/standard/base][PATCH 1/1] bpf: Reject variable offset alu on PTR_TO_FLOW_KEYS CAUTION: This email comes from a non Wind River email account! Do not click links or open attachments unless you recognize the sender and know the content is safe. In message: Re: [linux-yocto][v5.10/standard/base][PATCH 1/1] bpf: Reject variable offset alu on PTR_TO_FLOW_KEYS on 18/07/2024 Polampalli, Archana wrote: > Hi Bruce, > > This commit is not backported to older stable kernels, therefore backported it > from 5.15.y series. Kindly approve. Can you double check against the linux-yocto -stable updates that I pushed a few days ago ? I'm seeing this commit already in my tree. Bruce > > Regards, > Archana > ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ > From: [email protected] <[email protected]> > on behalf of Polampalli, Archana via lists.yoctoproject.org > <archana.polampalli > [email protected]> > Sent: Thursday, July 18, 2024 12:15 > To: [email protected] <[email protected]> > Cc: [email protected] <[email protected]> > Subject: [linux-yocto][v5.10/standard/base][PATCH 1/1] bpf: Reject variable > offset alu on PTR_TO_FLOW_KEYS > > From: Hao Sun <[email protected]> > > [ Upstream commit 22c7fa171a02d310e3a3f6ed46a698ca8a0060ed ] > > For PTR_TO_FLOW_KEYS, check_flow_keys_access() only uses fixed off > for validation. However, variable offset ptr alu is not prohibited > for this ptr kind. So the variable offset is not checked. > > The following prog is accepted: > > func#0 @0 > 0: R1=ctx() R10=fp0 > 0: (bf) r6 = r1 ; R1=ctx() R6_w=ctx() > 1: (79) r7 = *(u64 *)(r6 +144) ; R6_w=ctx() R7_w=flow_keys() > 2: (b7) r8 = 1024 ; R8_w=1024 > 3: (37) r8 /= 1 ; R8_w=scalar() > 4: (57) r8 &= 1024 ; R8_w=scalar(smin=smin32=0, > smax=umax=smax32=umax32=1024,var_off=(0x0; 0x400)) > 5: (0f) r7 += r8 > mark_precise: frame0: last_idx 5 first_idx 0 subseq_idx -1 > mark_precise: frame0: regs=r8 stack= before 4: (57) r8 &= 1024 > mark_precise: frame0: regs=r8 stack= before 3: (37) r8 /= 1 > mark_precise: frame0: regs=r8 stack= before 2: (b7) r8 = 1024 > 6: R7_w=flow_keys(smin=smin32=0,smax=umax=smax32=umax32=1024,var_off > =(0x0; 0x400)) R8_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=1024, > var_off=(0x0; 0x400)) > 6: (79) r0 = *(u64 *)(r7 +0) ; R0_w=scalar() > 7: (95) exit > > This prog loads flow_keys to r7, and adds the variable offset r8 > to r7, and finally causes out-of-bounds access: > > BUG: unable to handle page fault for address: ffffc90014c80038 > [...] > Call Trace: > <TASK> > bpf_dispatcher_nop_func include/linux/bpf.h:1231 [inline] > __bpf_prog_run include/linux/filter.h:651 [inline] > bpf_prog_run include/linux/filter.h:658 [inline] > bpf_prog_run_pin_on_cpu include/linux/filter.h:675 [inline] > bpf_flow_dissect+0x15f/0x350 net/core/flow_dissector.c:991 > bpf_prog_test_run_flow_dissector+0x39d/0x620 net/bpf/test_run.c:1359 > bpf_prog_test_run kernel/bpf/syscall.c:4107 [inline] > __sys_bpf+0xf8f/0x4560 kernel/bpf/syscall.c:5475 > __do_sys_bpf kernel/bpf/syscall.c:5561 [inline] > __se_sys_bpf kernel/bpf/syscall.c:5559 [inline] > __x64_sys_bpf+0x73/0xb0 kernel/bpf/syscall.c:5559 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x63/0x6b > > Fix this by rejecting ptr alu with variable offset on flow_keys. > Applying the patch rejects the program with "R7 pointer arithmetic > on flow_keys prohibited". > > Fixes: d58e468b1112 ("flow_dissector: implements flow dissector BPF hook") > Signed-off-by: Hao Sun <[email protected]> > Signed-off-by: Daniel Borkmann <[email protected]> > Acked-by: Yonghong Song <[email protected]> > Link: https://lore.kernel.org/bpf/[email protected] > > Signed-off-by: Archana Polampalli <[email protected]> > --- > kernel/bpf/verifier.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c > index 25f8a8716e88..e2818d4d5d1b 100644 > --- a/kernel/bpf/verifier.c > +++ b/kernel/bpf/verifier.c > @@ -6250,6 +6250,10 @@ static int adjust_ptr_min_max_vals(struct > bpf_verifier_env *env, > } > > switch (ptr_reg->type) { > + case PTR_TO_FLOW_KEYS: > + if (known) > + break; > + fallthrough; > case PTR_TO_MAP_VALUE_OR_NULL: > verbose(env, "R%d pointer arithmetic on %s prohibited, > null-check it first\n", > dst, reg_type_str[ptr_reg->type]); > -- > 2.40.0 >
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