<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/tools/lib/bpf, branch v6.12.91</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>bpf: reject negative CO-RE accessor indices in bpf_core_parse_spec()</title>
<updated>2026-05-23T11:04:23+00:00</updated>
<author>
<name>Weiming Shi</name>
<email>bestswngs@gmail.com</email>
</author>
<published>2026-04-04T16:12:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=36a9012f76ba8d9189ae56a1f8bb7c87c07a1f3a'/>
<id>36a9012f76ba8d9189ae56a1f8bb7c87c07a1f3a</id>
<content type='text'>
[ Upstream commit 1c22483a2c4bbf747787f328392ca3e68619c4dc ]

CO-RE accessor strings are colon-separated indices that describe a path
from a root BTF type to a target field, e.g. "0:1:2" walks through
nested struct members. bpf_core_parse_spec() parses each component with
sscanf("%d"), so negative values like -1 are silently accepted.  The
subsequent bounds checks (access_idx &gt;= btf_vlen(t)) only guard the
upper bound and always pass for negative values because C integer
promotion converts the __u16 btf_vlen result to int, making the
comparison (int)(-1) &gt;= (int)(N) false for any positive N.

When -1 reaches btf_member_bit_offset() it gets cast to u32 0xffffffff,
producing an out-of-bounds read far past the members array.  A crafted
BPF program with a negative CO-RE accessor on any struct that exists in
vmlinux BTF (e.g. task_struct) crashes the kernel deterministically
during BPF_PROG_LOAD on any system with CONFIG_DEBUG_INFO_BTF=y
(default on major distributions).  The bug is reachable with CAP_BPF:

 BUG: unable to handle page fault for address: ffffed11818b6626
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 Oops: Oops: 0000 [#1] SMP KASAN NOPTI
 CPU: 0 UID: 0 PID: 85 Comm: poc Not tainted 7.0.0-rc6 #18 PREEMPT(full)
 RIP: 0010:bpf_core_parse_spec (tools/lib/bpf/relo_core.c:354)
 RAX: 00000000ffffffff
 Call Trace:
  &lt;TASK&gt;
  bpf_core_calc_relo_insn (tools/lib/bpf/relo_core.c:1321)
  bpf_core_apply (kernel/bpf/btf.c:9507)
  check_core_relo (kernel/bpf/verifier.c:19475)
  bpf_check (kernel/bpf/verifier.c:26031)
  bpf_prog_load (kernel/bpf/syscall.c:3089)
  __sys_bpf (kernel/bpf/syscall.c:6228)
  &lt;/TASK&gt;

CO-RE accessor indices are inherently non-negative (struct member index,
array element index, or enumerator index), so reject them immediately
after parsing.

Fixes: ddc7c3042614 ("libbpf: implement BPF CO-RE offset relocation algorithm")
Reported-by: Xiang Mei &lt;xmei5@asu.edu&gt;
Signed-off-by: Weiming Shi &lt;bestswngs@gmail.com&gt;
Reviewed-by: Emil Tsalapatis &lt;emil@etsalapatis.com&gt;
Acked-by: Paul Chaignon &lt;paul.chaignon@gmail.com&gt;
Link: https://lore.kernel.org/r/20260404161221.961828-2-bestswngs@gmail.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 1c22483a2c4bbf747787f328392ca3e68619c4dc ]

CO-RE accessor strings are colon-separated indices that describe a path
from a root BTF type to a target field, e.g. "0:1:2" walks through
nested struct members. bpf_core_parse_spec() parses each component with
sscanf("%d"), so negative values like -1 are silently accepted.  The
subsequent bounds checks (access_idx &gt;= btf_vlen(t)) only guard the
upper bound and always pass for negative values because C integer
promotion converts the __u16 btf_vlen result to int, making the
comparison (int)(-1) &gt;= (int)(N) false for any positive N.

When -1 reaches btf_member_bit_offset() it gets cast to u32 0xffffffff,
producing an out-of-bounds read far past the members array.  A crafted
BPF program with a negative CO-RE accessor on any struct that exists in
vmlinux BTF (e.g. task_struct) crashes the kernel deterministically
during BPF_PROG_LOAD on any system with CONFIG_DEBUG_INFO_BTF=y
(default on major distributions).  The bug is reachable with CAP_BPF:

 BUG: unable to handle page fault for address: ffffed11818b6626
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 Oops: Oops: 0000 [#1] SMP KASAN NOPTI
 CPU: 0 UID: 0 PID: 85 Comm: poc Not tainted 7.0.0-rc6 #18 PREEMPT(full)
 RIP: 0010:bpf_core_parse_spec (tools/lib/bpf/relo_core.c:354)
 RAX: 00000000ffffffff
 Call Trace:
  &lt;TASK&gt;
  bpf_core_calc_relo_insn (tools/lib/bpf/relo_core.c:1321)
  bpf_core_apply (kernel/bpf/btf.c:9507)
  check_core_relo (kernel/bpf/verifier.c:19475)
  bpf_check (kernel/bpf/verifier.c:26031)
  bpf_prog_load (kernel/bpf/syscall.c:3089)
  __sys_bpf (kernel/bpf/syscall.c:6228)
  &lt;/TASK&gt;

CO-RE accessor indices are inherently non-negative (struct member index,
array element index, or enumerator index), so reject them immediately
after parsing.

Fixes: ddc7c3042614 ("libbpf: implement BPF CO-RE offset relocation algorithm")
Reported-by: Xiang Mei &lt;xmei5@asu.edu&gt;
Signed-off-by: Weiming Shi &lt;bestswngs@gmail.com&gt;
Reviewed-by: Emil Tsalapatis &lt;emil@etsalapatis.com&gt;
Acked-by: Paul Chaignon &lt;paul.chaignon@gmail.com&gt;
Link: https://lore.kernel.org/r/20260404161221.961828-2-bestswngs@gmail.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpftool: Fix truncated netlink dumps</title>
<updated>2026-03-04T12:20:38+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2026-02-17T19:41:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6ed7864a5c1af874482734d969e7e1a567b71e32'/>
<id>6ed7864a5c1af874482734d969e7e1a567b71e32</id>
<content type='text'>
[ Upstream commit 3b39d73cc3379360a33eb583b17f21fe55e1288e ]

Netlink requires that the recv buffer used during dumps is at least
min(PAGE_SIZE, 8k) (see the man page). Otherwise the messages will
get truncated. Make sure bpftool follows this requirement, avoid
missing information on systems with large pages.

Acked-by: Quentin Monnet &lt;qmo@kernel.org&gt;
Fixes: 7084566a236f ("tools/bpftool: Remove libbpf_internal.h usage in bpftool")
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Link: https://lore.kernel.org/r/20260217194150.734701-1-kuba@kernel.org
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 3b39d73cc3379360a33eb583b17f21fe55e1288e ]

Netlink requires that the recv buffer used during dumps is at least
min(PAGE_SIZE, 8k) (see the man page). Otherwise the messages will
get truncated. Make sure bpftool follows this requirement, avoid
missing information on systems with large pages.

Acked-by: Quentin Monnet &lt;qmo@kernel.org&gt;
Fixes: 7084566a236f ("tools/bpftool: Remove libbpf_internal.h usage in bpftool")
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Link: https://lore.kernel.org/r/20260217194150.734701-1-kuba@kernel.org
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>libbpf: Fix OOB read in btf_dump_get_bitfield_value</title>
<updated>2026-03-04T12:19:33+00:00</updated>
<author>
<name>Varun R Mallya</name>
<email>varunrmallya@gmail.com</email>
</author>
<published>2026-01-06T23:35:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5731312c4cb54f031007d90f0a6afd58b8642455'/>
<id>5731312c4cb54f031007d90f0a6afd58b8642455</id>
<content type='text'>
[ Upstream commit 5714ca8cba5ed736f3733663c446cbee63a10a64 ]

When dumping bitfield data, btf_dump_get_bitfield_value() reads data
based on the underlying type's size (t-&gt;size). However, it does not
verify that the provided data buffer (data_sz) is large enough to
contain these bytes.

If btf_dump__dump_type_data() is called with a buffer smaller than
the type's size, this leads to an out-of-bounds read. This was
confirmed by AddressSanitizer in the linked issue.

Fix this by ensuring we do not read past the provided data_sz limit.

Fixes: a1d3cc3c5eca ("libbpf: Avoid use of __int128 in typed dump display")
Reported-by: Harrison Green &lt;harrisonmichaelgreen@gmail.com&gt;
Suggested-by: Alan Maguire &lt;alan.maguire@oracle.com&gt;
Signed-off-by: Varun R Mallya &lt;varunrmallya@gmail.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20260106233527.163487-1-varunrmallya@gmail.com

Closes: https://github.com/libbpf/libbpf/issues/928
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 5714ca8cba5ed736f3733663c446cbee63a10a64 ]

When dumping bitfield data, btf_dump_get_bitfield_value() reads data
based on the underlying type's size (t-&gt;size). However, it does not
verify that the provided data buffer (data_sz) is large enough to
contain these bytes.

If btf_dump__dump_type_data() is called with a buffer smaller than
the type's size, this leads to an out-of-bounds read. This was
confirmed by AddressSanitizer in the linked issue.

Fix this by ensuring we do not read past the provided data_sz limit.

Fixes: a1d3cc3c5eca ("libbpf: Avoid use of __int128 in typed dump display")
Reported-by: Harrison Green &lt;harrisonmichaelgreen@gmail.com&gt;
Suggested-by: Alan Maguire &lt;alan.maguire@oracle.com&gt;
Signed-off-by: Varun R Mallya &lt;varunrmallya@gmail.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20260106233527.163487-1-varunrmallya@gmail.com

Closes: https://github.com/libbpf/libbpf/issues/928
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>libbpf: Fix -Wdiscarded-qualifiers under C23</title>
<updated>2026-02-06T15:55:49+00:00</updated>
<author>
<name>Mikhail Gavrilov</name>
<email>mikhail.v.gavrilov@gmail.com</email>
</author>
<published>2025-12-06T09:28:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3dedeeecd1ae42a751721d83dc21877122cc1795'/>
<id>3dedeeecd1ae42a751721d83dc21877122cc1795</id>
<content type='text'>
commit d70f79fef65810faf64dbae1f3a1b5623cdb2345 upstream.

glibc ≥ 2.42 (GCC 15) defaults to -std=gnu23, which promotes
-Wdiscarded-qualifiers to an error.

In C23, strstr() and strchr() return "const char *".

Change variable types to const char * where the pointers are never
modified (res, sym_sfx, next_path).

Suggested-by: Florian Weimer &lt;fweimer@redhat.com&gt;
Suggested-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Signed-off-by: Mikhail Gavrilov &lt;mikhail.v.gavrilov@gmail.com&gt;
Link: https://lore.kernel.org/r/20251206092825.1471385-1-mikhail.v.gavrilov@gmail.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
[ shung-hsi.yu: needed to fix kernel build failure due to libbpf since glibc
  2.43+ (which adds 'const' qualifier to strstr). 'sym_sfx' hunk dropped because
  commit f8a05692de06 ("libbpf: Work around kernel inconsistently stripping
  '.llvm.' suffix") is not present. ]
Signed-off-by: Shung-Hsi Yu &lt;shung-hsi.yu@suse.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit d70f79fef65810faf64dbae1f3a1b5623cdb2345 upstream.

glibc ≥ 2.42 (GCC 15) defaults to -std=gnu23, which promotes
-Wdiscarded-qualifiers to an error.

In C23, strstr() and strchr() return "const char *".

Change variable types to const char * where the pointers are never
modified (res, sym_sfx, next_path).

Suggested-by: Florian Weimer &lt;fweimer@redhat.com&gt;
Suggested-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Signed-off-by: Mikhail Gavrilov &lt;mikhail.v.gavrilov@gmail.com&gt;
Link: https://lore.kernel.org/r/20251206092825.1471385-1-mikhail.v.gavrilov@gmail.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
[ shung-hsi.yu: needed to fix kernel build failure due to libbpf since glibc
  2.43+ (which adds 'const' qualifier to strstr). 'sym_sfx' hunk dropped because
  commit f8a05692de06 ("libbpf: Work around kernel inconsistently stripping
  '.llvm.' suffix") is not present. ]
Signed-off-by: Shung-Hsi Yu &lt;shung-hsi.yu@suse.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>libbpf: Fix parsing of multi-split BTF</title>
<updated>2025-12-18T12:54:53+00:00</updated>
<author>
<name>Alan Maguire</name>
<email>alan.maguire@oracle.com</email>
</author>
<published>2025-11-04T20:33:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=627be3c40095e39849739b51a05f9fa0cc3b24fc'/>
<id>627be3c40095e39849739b51a05f9fa0cc3b24fc</id>
<content type='text'>
[ Upstream commit 4f596acc260e691a2e348f64230392f3472feea3 ]

When creating multi-split BTF we correctly set the start string offset
to be the size of the base string section plus the base BTF start
string offset; the latter is needed for multi-split BTF since the
offset is non-zero there.

Unfortunately the BTF parsing case needed that logic and it was
missed.

Fixes: 4e29128a9ace ("libbpf/btf: Fix string handling to support multi-split BTF")
Signed-off-by: Alan Maguire &lt;alan.maguire@oracle.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20251104203309.318429-2-alan.maguire@oracle.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 4f596acc260e691a2e348f64230392f3472feea3 ]

When creating multi-split BTF we correctly set the start string offset
to be the size of the base string section plus the base BTF start
string offset; the latter is needed for multi-split BTF since the
offset is non-zero there.

Unfortunately the BTF parsing case needed that logic and it was
missed.

Fixes: 4e29128a9ace ("libbpf/btf: Fix string handling to support multi-split BTF")
Signed-off-by: Alan Maguire &lt;alan.maguire@oracle.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20251104203309.318429-2-alan.maguire@oracle.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>libbpf: Fix USDT SIB argument handling causing unrecognized register error</title>
<updated>2025-11-13T20:34:03+00:00</updated>
<author>
<name>Jiawei Zhao</name>
<email>phoenix500526@163.com</email>
</author>
<published>2025-08-27T05:31:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4aeae7cc715630b5e087cf7b3a0239f22f737cba'/>
<id>4aeae7cc715630b5e087cf7b3a0239f22f737cba</id>
<content type='text'>
[ Upstream commit 758acb9ccfdbf854b55abaceaf1f3f229cde3d19 ]

On x86-64, USDT arguments can be specified using Scale-Index-Base (SIB)
addressing, e.g. "1@-96(%rbp,%rax,8)". The current USDT implementation
in libbpf cannot parse this format, causing `bpf_program__attach_usdt()`
to fail with -ENOENT (unrecognized register).

This patch fixes this by implementing the necessary changes:
- add correct handling for SIB-addressed arguments in `bpf_usdt_arg`.
- add adaptive support to `__bpf_usdt_arg_type` and
  `__bpf_usdt_arg_spec` to represent SIB addressing parameters.

Signed-off-by: Jiawei Zhao &lt;phoenix500526@163.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250827053128.1301287-2-phoenix500526@163.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 758acb9ccfdbf854b55abaceaf1f3f229cde3d19 ]

On x86-64, USDT arguments can be specified using Scale-Index-Base (SIB)
addressing, e.g. "1@-96(%rbp,%rax,8)". The current USDT implementation
in libbpf cannot parse this format, causing `bpf_program__attach_usdt()`
to fail with -ENOENT (unrecognized register).

This patch fixes this by implementing the necessary changes:
- add correct handling for SIB-addressed arguments in `bpf_usdt_arg`.
- add adaptive support to `__bpf_usdt_arg_type` and
  `__bpf_usdt_arg_spec` to represent SIB addressing parameters.

Signed-off-by: Jiawei Zhao &lt;phoenix500526@163.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250827053128.1301287-2-phoenix500526@163.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>libbpf: Fix powerpc's stack register definition in bpf_tracing.h</title>
<updated>2025-11-13T20:33:58+00:00</updated>
<author>
<name>Andrii Nakryiko</name>
<email>andrii@kernel.org</email>
</author>
<published>2025-10-20T20:36:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=10e2d2d16ab4802e35b4c8d7147aea715428fed9'/>
<id>10e2d2d16ab4802e35b4c8d7147aea715428fed9</id>
<content type='text'>
[ Upstream commit 7221b9caf84b3294688228a19273d74ea19a2ee4 ]

retsnoop's build on powerpc (ppc64le) architecture ([0]) failed due to
wrong definition of PT_REGS_SP() macro. Looking at powerpc's
implementation of stack unwinding in perf_callchain_user_64() clearly
shows that stack pointer register is gpr[1].

Fix libbpf's definition of __PT_SP_REG for powerpc to fix all this.

  [0] https://kojipkgs.fedoraproject.org/work/tasks/1544/137921544/build.log

Fixes: 138d6153a139 ("samples/bpf: Enable powerpc support")
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Reviewed-by: Naveen N Rao (AMD) &lt;naveen@kernel.org&gt;
Link: https://lore.kernel.org/r/20251020203643.989467-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 7221b9caf84b3294688228a19273d74ea19a2ee4 ]

retsnoop's build on powerpc (ppc64le) architecture ([0]) failed due to
wrong definition of PT_REGS_SP() macro. Looking at powerpc's
implementation of stack unwinding in perf_callchain_user_64() clearly
shows that stack pointer register is gpr[1].

Fix libbpf's definition of __PT_SP_REG for powerpc to fix all this.

  [0] https://kojipkgs.fedoraproject.org/work/tasks/1544/137921544/build.log

Fixes: 138d6153a139 ("samples/bpf: Enable powerpc support")
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Reviewed-by: Naveen N Rao (AMD) &lt;naveen@kernel.org&gt;
Link: https://lore.kernel.org/r/20251020203643.989467-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>libbpf: Fix error when st-prefix_ops and ops from differ btf</title>
<updated>2025-10-15T10:00:04+00:00</updated>
<author>
<name>D. Wythe</name>
<email>alibuda@linux.alibaba.com</email>
</author>
<published>2025-09-26T07:17:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9f57ad89c7c2bea9d24dacb29e761407e8eee2da'/>
<id>9f57ad89c7c2bea9d24dacb29e761407e8eee2da</id>
<content type='text'>
[ Upstream commit 0cc114dc358cf8da2ca23a366e761e89a46ca277 ]

When a module registers a struct_ops, the struct_ops type and its
corresponding map_value type ("bpf_struct_ops_") may reside in different
btf objects, here are four possible case:

+--------+---------------+-------------+---------------------------------+
|        |bpf_struct_ops_| xxx_ops     |                                 |
+--------+---------------+-------------+---------------------------------+
| case 0 | btf_vmlinux   | btf_vmlinux | be used and reg only in vmlinux |
+--------+---------------+-------------+---------------------------------+
| case 1 | btf_vmlinux   | mod_btf     | INVALID                         |
+--------+---------------+-------------+---------------------------------+
| case 2 | mod_btf       | btf_vmlinux | reg in mod but be used both in  |
|        |               |             | vmlinux and mod.                |
+--------+---------------+-------------+---------------------------------+
| case 3 | mod_btf       | mod_btf     | be used and reg only in mod     |
+--------+---------------+-------------+---------------------------------+

Currently we figure out the mod_btf by searching with the struct_ops type,
which makes it impossible to figure out the mod_btf when the struct_ops
type is in btf_vmlinux while it's corresponding map_value type is in
mod_btf (case 2).

The fix is to use the corresponding map_value type ("bpf_struct_ops_")
as the lookup anchor instead of the struct_ops type to figure out the
`btf` and `mod_btf` via find_ksym_btf_id(), and then we can locate
the kern_type_id via btf__find_by_name_kind() with the `btf` we just
obtained from find_ksym_btf_id().

With this change the lookup obtains the correct btf and mod_btf for case 2,
preserves correct behavior for other valid cases, and still fails as
expected for the invalid scenario (case 1).

Fixes: 590a00888250 ("bpf: libbpf: Add STRUCT_OPS support")
Signed-off-by: D. Wythe &lt;alibuda@linux.alibaba.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250926071751.108293-1-alibuda@linux.alibaba.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 0cc114dc358cf8da2ca23a366e761e89a46ca277 ]

When a module registers a struct_ops, the struct_ops type and its
corresponding map_value type ("bpf_struct_ops_") may reside in different
btf objects, here are four possible case:

+--------+---------------+-------------+---------------------------------+
|        |bpf_struct_ops_| xxx_ops     |                                 |
+--------+---------------+-------------+---------------------------------+
| case 0 | btf_vmlinux   | btf_vmlinux | be used and reg only in vmlinux |
+--------+---------------+-------------+---------------------------------+
| case 1 | btf_vmlinux   | mod_btf     | INVALID                         |
+--------+---------------+-------------+---------------------------------+
| case 2 | mod_btf       | btf_vmlinux | reg in mod but be used both in  |
|        |               |             | vmlinux and mod.                |
+--------+---------------+-------------+---------------------------------+
| case 3 | mod_btf       | mod_btf     | be used and reg only in mod     |
+--------+---------------+-------------+---------------------------------+

Currently we figure out the mod_btf by searching with the struct_ops type,
which makes it impossible to figure out the mod_btf when the struct_ops
type is in btf_vmlinux while it's corresponding map_value type is in
mod_btf (case 2).

The fix is to use the corresponding map_value type ("bpf_struct_ops_")
as the lookup anchor instead of the struct_ops type to figure out the
`btf` and `mod_btf` via find_ksym_btf_id(), and then we can locate
the kern_type_id via btf__find_by_name_kind() with the `btf` we just
obtained from find_ksym_btf_id().

With this change the lookup obtains the correct btf and mod_btf for case 2,
preserves correct behavior for other valid cases, and still fails as
expected for the invalid scenario (case 1).

Fixes: 590a00888250 ("bpf: libbpf: Add STRUCT_OPS support")
Signed-off-by: D. Wythe &lt;alibuda@linux.alibaba.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250926071751.108293-1-alibuda@linux.alibaba.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>libbpf: Fix reuse of DEVMAP</title>
<updated>2025-10-15T09:59:56+00:00</updated>
<author>
<name>Yureka Lilian</name>
<email>yuka@yuka.dev</email>
</author>
<published>2025-08-14T18:01:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=623542791a3fa53790829d1e0c79b7309156684d'/>
<id>623542791a3fa53790829d1e0c79b7309156684d</id>
<content type='text'>
[ Upstream commit 6c6b4146deb12d20f42490d5013f2043df942161 ]

Previously, re-using pinned DEVMAP maps would always fail, because
get_map_info on a DEVMAP always returns flags with BPF_F_RDONLY_PROG set,
but BPF_F_RDONLY_PROG being set on a map during creation is invalid.

Thus, ignore the BPF_F_RDONLY_PROG flag in the flags returned from
get_map_info when checking for compatibility with an existing DEVMAP.

The same problem is handled in a third-party ebpf library:
- https://github.com/cilium/ebpf/issues/925
- https://github.com/cilium/ebpf/pull/930

Fixes: 0cdbb4b09a06 ("devmap: Allow map lookups from eBPF")
Signed-off-by: Yureka Lilian &lt;yuka@yuka.dev&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250814180113.1245565-3-yuka@yuka.dev
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 6c6b4146deb12d20f42490d5013f2043df942161 ]

Previously, re-using pinned DEVMAP maps would always fail, because
get_map_info on a DEVMAP always returns flags with BPF_F_RDONLY_PROG set,
but BPF_F_RDONLY_PROG being set on a map during creation is invalid.

Thus, ignore the BPF_F_RDONLY_PROG flag in the flags returned from
get_map_info when checking for compatibility with an existing DEVMAP.

The same problem is handled in a third-party ebpf library:
- https://github.com/cilium/ebpf/issues/925
- https://github.com/cilium/ebpf/pull/930

Fixes: 0cdbb4b09a06 ("devmap: Allow map lookups from eBPF")
Signed-off-by: Yureka Lilian &lt;yuka@yuka.dev&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250814180113.1245565-3-yuka@yuka.dev
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>libbpf: Verify that arena map exists when adding arena relocations</title>
<updated>2025-08-20T16:30:29+00:00</updated>
<author>
<name>Eduard Zingerman</name>
<email>eddyz87@gmail.com</email>
</author>
<published>2025-07-18T22:20:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9ea8fb379fdfd197f71e873676ffefa1e931d87a'/>
<id>9ea8fb379fdfd197f71e873676ffefa1e931d87a</id>
<content type='text'>
[ Upstream commit 42be23e8f2dcb100cb9944b2b54b6bf41aff943d ]

Fuzzer reported a memory access error in bpf_program__record_reloc()
that happens when:
- ".addr_space.1" section exists
- there is a relocation referencing this section
- there are no arena maps defined in BTF.

Sanity checks for maps existence are already present in
bpf_program__record_reloc(), hence this commit adds another one.

[1] https://github.com/libbpf/libbpf/actions/runs/16375110681/job/46272998064

Signed-off-by: Eduard Zingerman &lt;eddyz87@gmail.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250718222059.281526-1-eddyz87@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 42be23e8f2dcb100cb9944b2b54b6bf41aff943d ]

Fuzzer reported a memory access error in bpf_program__record_reloc()
that happens when:
- ".addr_space.1" section exists
- there is a relocation referencing this section
- there are no arena maps defined in BTF.

Sanity checks for maps existence are already present in
bpf_program__record_reloc(), hence this commit adds another one.

[1] https://github.com/libbpf/libbpf/actions/runs/16375110681/job/46272998064

Signed-off-by: Eduard Zingerman &lt;eddyz87@gmail.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250718222059.281526-1-eddyz87@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
