Bug 2219196

Summary: bpf-biosnoop fails to run
Product: Red Hat Enterprise Linux 9 Reporter: Carlos Rodriguez-Fernandez <carlosrodrifernandez>
Component: bccAssignee: Jerome Marchand <jmarchan>
Status: CLOSED MIGRATED QA Contact:
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: CentOS StreamCC: bfubel, bstinson, ctrautma, jmarchan, jwboyer, ldoskova, rdossant
Target Milestone: rcKeywords: MigratedToJIRA, Triaged
Target Release: ---Flags: pm-rhel: mirror+
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2023-09-25 17:06:10 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description Carlos Rodriguez-Fernandez 2023-07-02 23:06:07 UTC
Description of problem:


bpf-biosnoop fails to run.

```
bpf-biosnoop 1
libbpf: prog 'block_rq_complete': BPF program load failed: Permission denied
libbpf: prog 'block_rq_complete': -- BEGIN PROG LOAD LOG --
reg type unsupported for arg#0 function block_rq_complete#142
0: R1=ctx(off=0,imm=0) R10=fp0
; int BPF_PROG(block_rq_complete, struct request *rq, int error,
0: (bf) r6 = r1                       ; R1=ctx(off=0,imm=0) R6_w=ctx(off=0,imm=0)
; int BPF_PROG(block_rq_complete, struct request *rq, int error,
1: (79) r1 = *(u64 *)(r6 +0)
func 'block_rq_complete' arg0 has btf_id 6289 type STRUCT 'request'
2: R1_w=trusted_ptr_request(off=0,imm=0) R6_w=ctx(off=0,imm=0)
2: (7b) *(u64 *)(r10 -8) = r1         ; R1_w=trusted_ptr_request(off=0,imm=0) R10=fp0 fp-8_w=trusted_ptr_
; if (filter_cg && !bpf_current_task_under_cgroup(&cgroup_map, 0))
3: (18) r1 = 0xffffb81ac011c000       ; R1_w=map_value(off=0,ks=4,vs=8,imm=0)
5: (71) r1 = *(u8 *)(r1 +0)           ; R1_w=0
; if (filter_cg && !bpf_current_task_under_cgroup(&cgroup_map, 0))
6: (15) if r1 == 0x0 goto pc+5        ; R1_w=0
; u64 ts = bpf_ktime_get_ns();
12: (85) call bpf_ktime_get_ns#5      ; R0=scalar()
13: (bf) r9 = r0                      ; R0=scalar(id=1) R9_w=scalar(id=1)
14: (b7) r7 = 0                       ; R7_w=0
; struct event event = {};
15: (7b) *(u64 *)(r10 -16) = r7       ; R7_w=0 R10=fp0 fp-16_w=00000000
16: (7b) *(u64 *)(r10 -24) = r7       ; R7_w=0 R10=fp0 fp-24_w=00000000
17: (7b) *(u64 *)(r10 -32) = r7       ; R7_w=0 R10=fp0 fp-32_w=00000000
18: (7b) *(u64 *)(r10 -40) = r7       ; R7_w=0 R10=fp0 fp-40_w=00000000
19: (7b) *(u64 *)(r10 -48) = r7       ; R7_w=0 R10=fp0 fp-48_w=00000000
20: (7b) *(u64 *)(r10 -56) = r7       ; R7_w=0 R10=fp0 fp-56_w=00000000
21: (7b) *(u64 *)(r10 -64) = r7       ; R7_w=0 R10=fp0 fp-64_w=00000000
22: (7b) *(u64 *)(r10 -72) = r7       ; R7_w=0 R10=fp0 fp-72_w=00000000
23: (bf) r2 = r10                     ; R2_w=fp0 R10=fp0
; u64 ts = bpf_ktime_get_ns();
24: (07) r2 += -8                     ; R2_w=fp-8
; stagep = bpf_map_lookup_elem(&start, &rq);
25: (18) r1 = 0xffff93cadb714000      ; R1_w=map_ptr(off=0,ks=8,vs=24,imm=0)
27: (85) call bpf_map_lookup_elem#1   ; R0_w=map_value_or_null(id=2,off=0,ks=8,vs=24,imm=0)
28: (bf) r8 = r0                      ; R0_w=map_value_or_null(id=2,off=0,ks=8,vs=24,imm=0) R8_w=map_value_or_null(id=2,off=0,ks=8,vs=24,imm=0)
; if (!stagep)
29: (15) if r8 == 0x0 goto pc+82      ; R8_w=map_value(off=0,ks=8,vs=24,imm=0)
; delta = (s64)(ts - stagep->issue);
30: (79) r1 = *(u64 *)(r8 +8)         ; R1_w=scalar() R8_w=map_value(off=0,ks=8,vs=24,imm=0)
31: (7b) *(u64 *)(r10 -96) = r9       ; R9_w=scalar(id=1) R10=fp0 fp-96_w=mmmmmmmm
; delta = (s64)(ts - stagep->issue);
32: (1f) r9 -= r1                     ; R1=scalar() R9=scalar()
; if (delta < 0)
33: (6d) if r7 s> r9 goto pc+68       ; R7=0 R9=scalar(umax=9223372036854775807,var_off=(0x0; 0x7fffffffffffffff))
34: (bf) r2 = r10                     ; R2_w=fp0 R10=fp0
; 
35: (07) r2 += -8                     ; R2_w=fp-8
; piddatap = bpf_map_lookup_elem(&infobyreq, &rq);
36: (18) r1 = 0xffff93cadb715c00      ; R1_w=map_ptr(off=0,ks=8,vs=20,imm=0)
38: (85) call bpf_map_lookup_elem#1   ; R0_w=map_value_or_null(id=3,off=0,ks=8,vs=20,imm=0)
; if (!piddatap) {
39: (55) if r0 != 0x0 goto pc+3       ; R0_w=0
40: (b7) r1 = 63                      ; R1_w=63
; event.comm[0] = '?';
41: (73) *(u8 *)(r10 -72) = r1        ; R1_w=63 R10=fp0 fp-72=63
42: (05) goto pc+12
; event.delta = delta;
55: (7b) *(u64 *)(r10 -56) = r9       ; R9=scalar(umax=9223372036854775807,var_off=(0x0; 0x7fffffffffffffff)) R10=fp0 fp-56_w=
; if (targ_queued && BPF_CORE_READ(rq, q, elevator)) {
56: (18) r1 = 0xffffb81ac011c001      ; R1_w=map_value(off=1,ks=4,vs=8,imm=0)
58: (71) r1 = *(u8 *)(r1 +0)          ; R1_w=0
59: (79) r7 = *(u64 *)(r10 -96)       ; R7_w=scalar() R10=fp0
; if (targ_queued && BPF_CORE_READ(rq, q, elevator)) {
60: (15) if r1 == 0x0 goto pc+22      ; R1_w=0
; event.ts = ts;
83: (7b) *(u64 *)(r10 -40) = r7       ; R7_w=scalar() R10=fp0 fp-40_w=mmmmmmmm
; event.sector = rq->__sector;
84: (79) r1 = *(u64 *)(r10 -8)        ; R1_w=scalar() R10=fp0
; event.sector = rq->__sector;
85: (79) r2 = *(u64 *)(r1 +48)
R1 invalid mem access 'scalar'
processed 43 insns (limit 1000000) max_states_per_insn 0 total_states 3 peak_states 3 mark_read 2
-- END PROG LOAD LOG --
libbpf: prog 'block_rq_complete': failed to load: -13
libbpf: failed to load object 'biosnoop_bpf'
libbpf: failed to load BPF skeleton 'biosnoop_bpf': -13
failed to load BPF object: -13
```

Version-Release number of selected component (if applicable):
Name         : libbpf-tools
Version      : 0.26.0
Release      : 3.el9

How reproducible:

Steps to Reproduce:
1. Download Centos Stream 9 QCOW2 and run it
2. run dnf install libbpf-tools
3. run bpf-biosnoop 1

Actual results:

```
libbpf: prog 'block_rq_complete': BPF program load failed: Permission denied
libbpf: prog 'block_rq_complete': -- BEGIN PROG LOAD LOG --
reg type unsupported for arg#0 function block_rq_complete#142
0: R1=ctx(off=0,imm=0) R10=fp0
; int BPF_PROG(block_rq_complete, struct request *rq, int error,
0: (bf) r6 = r1                       ; R1=ctx(off=0,imm=0) R6_w=ctx(off=0,imm=0)
; int BPF_PROG(block_rq_complete, struct request *rq, int error,
1: (79) r1 = *(u64 *)(r6 +0)
func 'block_rq_complete' arg0 has btf_id 6289 type STRUCT 'request'
2: R1_w=trusted_ptr_request(off=0,imm=0) R6_w=ctx(off=0,imm=0)
2: (7b) *(u64 *)(r10 -8) = r1         ; R1_w=trusted_ptr_request(off=0,imm=0) R10=fp0 fp-8_w=trusted_ptr_
; if (filter_cg && !bpf_current_task_under_cgroup(&cgroup_map, 0))
3: (18) r1 = 0xffffb81ac011c000       ; R1_w=map_value(off=0,ks=4,vs=8,imm=0)
5: (71) r1 = *(u8 *)(r1 +0)           ; R1_w=0
; if (filter_cg && !bpf_current_task_under_cgroup(&cgroup_map, 0))
6: (15) if r1 == 0x0 goto pc+5        ; R1_w=0
; u64 ts = bpf_ktime_get_ns();
12: (85) call bpf_ktime_get_ns#5      ; R0=scalar()
13: (bf) r9 = r0                      ; R0=scalar(id=1) R9_w=scalar(id=1)
14: (b7) r7 = 0                       ; R7_w=0
; struct event event = {};
15: (7b) *(u64 *)(r10 -16) = r7       ; R7_w=0 R10=fp0 fp-16_w=00000000
16: (7b) *(u64 *)(r10 -24) = r7       ; R7_w=0 R10=fp0 fp-24_w=00000000
17: (7b) *(u64 *)(r10 -32) = r7       ; R7_w=0 R10=fp0 fp-32_w=00000000
18: (7b) *(u64 *)(r10 -40) = r7       ; R7_w=0 R10=fp0 fp-40_w=00000000
19: (7b) *(u64 *)(r10 -48) = r7       ; R7_w=0 R10=fp0 fp-48_w=00000000
20: (7b) *(u64 *)(r10 -56) = r7       ; R7_w=0 R10=fp0 fp-56_w=00000000
21: (7b) *(u64 *)(r10 -64) = r7       ; R7_w=0 R10=fp0 fp-64_w=00000000
22: (7b) *(u64 *)(r10 -72) = r7       ; R7_w=0 R10=fp0 fp-72_w=00000000
23: (bf) r2 = r10                     ; R2_w=fp0 R10=fp0
; u64 ts = bpf_ktime_get_ns();
24: (07) r2 += -8                     ; R2_w=fp-8
; stagep = bpf_map_lookup_elem(&start, &rq);
25: (18) r1 = 0xffff93cadb714000      ; R1_w=map_ptr(off=0,ks=8,vs=24,imm=0)
27: (85) call bpf_map_lookup_elem#1   ; R0_w=map_value_or_null(id=2,off=0,ks=8,vs=24,imm=0)
28: (bf) r8 = r0                      ; R0_w=map_value_or_null(id=2,off=0,ks=8,vs=24,imm=0) R8_w=map_value_or_null(id=2,off=0,ks=8,vs=24,imm=0)
; if (!stagep)
29: (15) if r8 == 0x0 goto pc+82      ; R8_w=map_value(off=0,ks=8,vs=24,imm=0)
; delta = (s64)(ts - stagep->issue);
30: (79) r1 = *(u64 *)(r8 +8)         ; R1_w=scalar() R8_w=map_value(off=0,ks=8,vs=24,imm=0)
31: (7b) *(u64 *)(r10 -96) = r9       ; R9_w=scalar(id=1) R10=fp0 fp-96_w=mmmmmmmm
; delta = (s64)(ts - stagep->issue);
32: (1f) r9 -= r1                     ; R1=scalar() R9=scalar()
; if (delta < 0)
33: (6d) if r7 s> r9 goto pc+68       ; R7=0 R9=scalar(umax=9223372036854775807,var_off=(0x0; 0x7fffffffffffffff))
34: (bf) r2 = r10                     ; R2_w=fp0 R10=fp0
; 
35: (07) r2 += -8                     ; R2_w=fp-8
; piddatap = bpf_map_lookup_elem(&infobyreq, &rq);
36: (18) r1 = 0xffff93cadb715c00      ; R1_w=map_ptr(off=0,ks=8,vs=20,imm=0)
38: (85) call bpf_map_lookup_elem#1   ; R0_w=map_value_or_null(id=3,off=0,ks=8,vs=20,imm=0)
; if (!piddatap) {
39: (55) if r0 != 0x0 goto pc+3       ; R0_w=0
40: (b7) r1 = 63                      ; R1_w=63
; event.comm[0] = '?';
41: (73) *(u8 *)(r10 -72) = r1        ; R1_w=63 R10=fp0 fp-72=63
42: (05) goto pc+12
; event.delta = delta;
55: (7b) *(u64 *)(r10 -56) = r9       ; R9=scalar(umax=9223372036854775807,var_off=(0x0; 0x7fffffffffffffff)) R10=fp0 fp-56_w=
; if (targ_queued && BPF_CORE_READ(rq, q, elevator)) {
56: (18) r1 = 0xffffb81ac011c001      ; R1_w=map_value(off=1,ks=4,vs=8,imm=0)
58: (71) r1 = *(u8 *)(r1 +0)          ; R1_w=0
59: (79) r7 = *(u64 *)(r10 -96)       ; R7_w=scalar() R10=fp0
; if (targ_queued && BPF_CORE_READ(rq, q, elevator)) {
60: (15) if r1 == 0x0 goto pc+22      ; R1_w=0
; event.ts = ts;
83: (7b) *(u64 *)(r10 -40) = r7       ; R7_w=scalar() R10=fp0 fp-40_w=mmmmmmmm
; event.sector = rq->__sector;
84: (79) r1 = *(u64 *)(r10 -8)        ; R1_w=scalar() R10=fp0
; event.sector = rq->__sector;
85: (79) r2 = *(u64 *)(r1 +48)
R1 invalid mem access 'scalar'
processed 43 insns (limit 1000000) max_states_per_insn 0 total_states 3 peak_states 3 mark_read 2
-- END PROG LOAD LOG --
libbpf: prog 'block_rq_complete': failed to load: -13
libbpf: failed to load object 'biosnoop_bpf'
libbpf: failed to load BPF skeleton 'biosnoop_bpf': -13
failed to load BPF object: -13
```

Expected results:
It doesn't error but works as intended

Additional info:

Comment 1 Jerome Marchand 2023-07-21 13:16:15 UTC
Looks like the following commit might fix it:
02daf8d8 libbpf-tools/biosnoop: Fix out-of-bounds accessing of rq

Comment 2 RHEL Program Management 2023-09-25 16:51:09 UTC
Issue migration from Bugzilla to Jira is in process at this time. This will be the last message in Jira copied from the Bugzilla bug.

Comment 3 RHEL Program Management 2023-09-25 17:06:10 UTC
This BZ has been automatically migrated to the issues.redhat.com Red Hat Issue Tracker. All future work related to this report will be managed there.

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