<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/tools/lib, branch v6.15.3</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>libbpf: Use proper errno value in nlattr</title>
<updated>2025-06-19T13:39:52+00:00</updated>
<author>
<name>Anton Protopopov</name>
<email>a.s.protopopov@gmail.com</email>
</author>
<published>2025-05-10T18:20:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=879beb3f03f8f1340f4921eb9e65fa6931bf22d2'/>
<id>879beb3f03f8f1340f4921eb9e65fa6931bf22d2</id>
<content type='text'>
[ Upstream commit fd5fd538a1f4b34cee6823ba0ddda2f7a55aca96 ]

Return value of the validate_nla() function can be propagated all the
way up to users of libbpf API. In case of error this libbpf version
of validate_nla returns -1 which will be seen as -EPERM from user's
point of view. Instead, return a more reasonable -EINVAL.

Fixes: bbf48c18ee0c ("libbpf: add error reporting in XDP")
Suggested-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Signed-off-by: Anton Protopopov &lt;a.s.protopopov@gmail.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250510182011.2246631-1-a.s.protopopov@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 fd5fd538a1f4b34cee6823ba0ddda2f7a55aca96 ]

Return value of the validate_nla() function can be propagated all the
way up to users of libbpf API. In case of error this libbpf version
of validate_nla returns -1 which will be seen as -EPERM from user's
point of view. Instead, return a more reasonable -EINVAL.

Fixes: bbf48c18ee0c ("libbpf: add error reporting in XDP")
Suggested-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Signed-off-by: Anton Protopopov &lt;a.s.protopopov@gmail.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250510182011.2246631-1-a.s.protopopov@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Fix uninitialized values in BPF_{CORE,PROBE}_READ</title>
<updated>2025-06-19T13:39:49+00:00</updated>
<author>
<name>Anton Protopopov</name>
<email>a.s.protopopov@gmail.com</email>
</author>
<published>2025-05-02T19:30:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1340a95ec972a45272cfda2a5856372cdf0cf00a'/>
<id>1340a95ec972a45272cfda2a5856372cdf0cf00a</id>
<content type='text'>
[ Upstream commit 41d4ce6df3f4945341ec509a840cc002a413b6cc ]

With the latest LLVM bpf selftests build will fail with
the following error message:

    progs/profiler.inc.h:710:31: error: default initialization of an object of type 'typeof ((parent_task)-&gt;real_cred-&gt;uid.val)' (aka 'const unsigned int') leaves the object uninitialized and is incompatible with C++ [-Werror,-Wdefault-const-init-unsafe]
      710 |         proc_exec_data-&gt;parent_uid = BPF_CORE_READ(parent_task, real_cred, uid.val);
          |                                      ^
    tools/testing/selftests/bpf/tools/include/bpf/bpf_core_read.h:520:35: note: expanded from macro 'BPF_CORE_READ'
      520 |         ___type((src), a, ##__VA_ARGS__) __r;                               \
          |                                          ^

This happens because BPF_CORE_READ (and other macro) declare the
variable __r using the ___type macro which can inherit const modifier
from intermediate types.

Fix this by using __typeof_unqual__, when supported. (And when it
is not supported, the problem shouldn't appear, as older compilers
haven't complained.)

Fixes: 792001f4f7aa ("libbpf: Add user-space variants of BPF_CORE_READ() family of macros")
Fixes: a4b09a9ef945 ("libbpf: Add non-CO-RE variants of BPF_CORE_READ() macro family")
Signed-off-by: Anton Protopopov &lt;a.s.protopopov@gmail.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250502193031.3522715-1-a.s.protopopov@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 41d4ce6df3f4945341ec509a840cc002a413b6cc ]

With the latest LLVM bpf selftests build will fail with
the following error message:

    progs/profiler.inc.h:710:31: error: default initialization of an object of type 'typeof ((parent_task)-&gt;real_cred-&gt;uid.val)' (aka 'const unsigned int') leaves the object uninitialized and is incompatible with C++ [-Werror,-Wdefault-const-init-unsafe]
      710 |         proc_exec_data-&gt;parent_uid = BPF_CORE_READ(parent_task, real_cred, uid.val);
          |                                      ^
    tools/testing/selftests/bpf/tools/include/bpf/bpf_core_read.h:520:35: note: expanded from macro 'BPF_CORE_READ'
      520 |         ___type((src), a, ##__VA_ARGS__) __r;                               \
          |                                          ^

This happens because BPF_CORE_READ (and other macro) declare the
variable __r using the ___type macro which can inherit const modifier
from intermediate types.

Fix this by using __typeof_unqual__, when supported. (And when it
is not supported, the problem shouldn't appear, as older compilers
haven't complained.)

Fixes: 792001f4f7aa ("libbpf: Add user-space variants of BPF_CORE_READ() family of macros")
Fixes: a4b09a9ef945 ("libbpf: Add non-CO-RE variants of BPF_CORE_READ() macro family")
Signed-off-by: Anton Protopopov &lt;a.s.protopopov@gmail.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250502193031.3522715-1-a.s.protopopov@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>libbpf: Use proper errno value in linker</title>
<updated>2025-06-19T13:39:48+00:00</updated>
<author>
<name>Anton Protopopov</name>
<email>a.s.protopopov@gmail.com</email>
</author>
<published>2025-04-30T12:08:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d19aa5c648eebb0e243f9f8e58d30a56da91e186'/>
<id>d19aa5c648eebb0e243f9f8e58d30a56da91e186</id>
<content type='text'>
[ Upstream commit 358b1c0f56ebb6996fcec7dcdcf6bae5dcbc8b6c ]

Return values of the linker_append_sec_data() and the
linker_append_elf_relos() functions are propagated all the
way up to users of libbpf API. In some error cases these
functions return -1 which will be seen as -EPERM from user's
point of view. Instead, return a more reasonable -EINVAL.

Fixes: faf6ed321cf6 ("libbpf: Add BPF static linker APIs")
Signed-off-by: Anton Protopopov &lt;a.s.protopopov@gmail.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250430120820.2262053-1-a.s.protopopov@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 358b1c0f56ebb6996fcec7dcdcf6bae5dcbc8b6c ]

Return values of the linker_append_sec_data() and the
linker_append_elf_relos() functions are propagated all the
way up to users of libbpf API. In some error cases these
functions return -1 which will be seen as -EPERM from user's
point of view. Instead, return a more reasonable -EINVAL.

Fixes: faf6ed321cf6 ("libbpf: Add BPF static linker APIs")
Signed-off-by: Anton Protopopov &lt;a.s.protopopov@gmail.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250430120820.2262053-1-a.s.protopopov@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Use thread-safe function pointer in libbpf_print</title>
<updated>2025-06-19T13:39:46+00:00</updated>
<author>
<name>Jonathan Wiepert</name>
<email>jonathan.wiepert@gmail.com</email>
</author>
<published>2025-04-24T22:14:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=07d74c1c976d496bc3b1f0c70e157795e8a7d9d8'/>
<id>07d74c1c976d496bc3b1f0c70e157795e8a7d9d8</id>
<content type='text'>
[ Upstream commit 91dbac4076537b464639953c055c460d2bdfc7ea ]

This patch fixes a thread safety bug where libbpf_print uses the
global variable storing the print function pointer rather than the local
variable that had the print function set via __atomic_load_n.

Fixes: f1cb927cdb62 ("libbpf: Ensure print callback usage is thread-safe")
Signed-off-by: Jonathan Wiepert &lt;jonathan.wiepert@gmail.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Mykyta Yatsenko &lt;mykyta.yatsenko5@gmail.com&gt;
Link: https://lore.kernel.org/bpf/20250424221457.793068-1-jonathan.wiepert@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 91dbac4076537b464639953c055c460d2bdfc7ea ]

This patch fixes a thread safety bug where libbpf_print uses the
global variable storing the print function pointer rather than the local
variable that had the print function set via __atomic_load_n.

Fixes: f1cb927cdb62 ("libbpf: Ensure print callback usage is thread-safe")
Signed-off-by: Jonathan Wiepert &lt;jonathan.wiepert@gmail.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Mykyta Yatsenko &lt;mykyta.yatsenko5@gmail.com&gt;
Link: https://lore.kernel.org/bpf/20250424221457.793068-1-jonathan.wiepert@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>libbpf: Remove sample_period init in perf_buffer</title>
<updated>2025-06-19T13:39:46+00:00</updated>
<author>
<name>Tao Chen</name>
<email>chen.dylane@linux.dev</email>
</author>
<published>2025-04-23T16:39:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c5a5553e3b5261cc68fd25d4ce1510f959ab2f1f'/>
<id>c5a5553e3b5261cc68fd25d4ce1510f959ab2f1f</id>
<content type='text'>
[ Upstream commit 64821d25f05ac468d435e61669ae745ce5a633ea ]

It seems that sample_period is not used in perf buffer. Actually, only
wakeup_events are meaningful to enable events aggregation for wakeup notification.
Remove sample_period setting code to avoid confusion.

Fixes: fb84b8224655 ("libbpf: add perf buffer API")
Signed-off-by: Tao Chen &lt;chen.dylane@linux.dev&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Acked-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250423163901.2983689-1-chen.dylane@linux.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 64821d25f05ac468d435e61669ae745ce5a633ea ]

It seems that sample_period is not used in perf buffer. Actually, only
wakeup_events are meaningful to enable events aggregation for wakeup notification.
Remove sample_period setting code to avoid confusion.

Fixes: fb84b8224655 ("libbpf: add perf buffer API")
Signed-off-by: Tao Chen &lt;chen.dylane@linux.dev&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Acked-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250423163901.2983689-1-chen.dylane@linux.dev
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>libbpf: Fix event name too long error</title>
<updated>2025-06-19T13:39:46+00:00</updated>
<author>
<name>Feng Yang</name>
<email>yangfeng@kylinos.cn</email>
</author>
<published>2025-04-17T01:48:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=220735551a40109222f2f900dc90290f8aca0143'/>
<id>220735551a40109222f2f900dc90290f8aca0143</id>
<content type='text'>
[ Upstream commit 4dde20b1aa85d69c4281eaac9a7cfa7d2b62ecf0 ]

When the binary path is excessively long, the generated probe_name in libbpf
exceeds the kernel's MAX_EVENT_NAME_LEN limit (64 bytes).
This causes legacy uprobe event attachment to fail with error code -22.

The fix reorders the fields to place the unique ID before the name.
This ensures that even if truncation occurs via snprintf, the unique ID
remains intact, preserving event name uniqueness. Additionally, explicit
checks with MAX_EVENT_NAME_LEN are added to enforce length constraints.

Before Fix:
	./test_progs -t attach_probe/kprobe-long_name
	......
	libbpf: failed to add legacy kprobe event for 'bpf_testmod_looooooooooooooooooooooooooooooong_name+0x0': -EINVAL
	libbpf: prog 'handle_kprobe': failed to create kprobe 'bpf_testmod_looooooooooooooooooooooooooooooong_name+0x0' perf event: -EINVAL
	test_attach_kprobe_long_event_name:FAIL:attach_kprobe_long_event_name unexpected error: -22
	test_attach_probe:PASS:uprobe_ref_ctr_cleanup 0 nsec
	#13/11   attach_probe/kprobe-long_name:FAIL
	#13      attach_probe:FAIL

	./test_progs -t attach_probe/uprobe-long_name
	......
	libbpf: failed to add legacy uprobe event for /root/linux-bpf/bpf-next/tools/testing/selftests/bpf/test_progs:0x13efd9: -EINVAL
	libbpf: prog 'handle_uprobe': failed to create uprobe '/root/linux-bpf/bpf-next/tools/testing/selftests/bpf/test_progs:0x13efd9' perf event: -EINVAL
	test_attach_uprobe_long_event_name:FAIL:attach_uprobe_long_event_name unexpected error: -22
	#13/10   attach_probe/uprobe-long_name:FAIL
	#13      attach_probe:FAIL
After Fix:
	./test_progs -t attach_probe/uprobe-long_name
	#13/10   attach_probe/uprobe-long_name:OK
	#13      attach_probe:OK
	Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED

	./test_progs -t attach_probe/kprobe-long_name
	#13/11   attach_probe/kprobe-long_name:OK
	#13      attach_probe:OK
	Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED

Fixes: 46ed5fc33db9 ("libbpf: Refactor and simplify legacy kprobe code")
Fixes: cc10623c6810 ("libbpf: Add legacy uprobe attaching support")
Signed-off-by: Hengqi Chen &lt;hengqi.chen@gmail.com&gt;
Signed-off-by: Feng Yang &lt;yangfeng@kylinos.cn&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250417014848.59321-2-yangfeng59949@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 4dde20b1aa85d69c4281eaac9a7cfa7d2b62ecf0 ]

When the binary path is excessively long, the generated probe_name in libbpf
exceeds the kernel's MAX_EVENT_NAME_LEN limit (64 bytes).
This causes legacy uprobe event attachment to fail with error code -22.

The fix reorders the fields to place the unique ID before the name.
This ensures that even if truncation occurs via snprintf, the unique ID
remains intact, preserving event name uniqueness. Additionally, explicit
checks with MAX_EVENT_NAME_LEN are added to enforce length constraints.

Before Fix:
	./test_progs -t attach_probe/kprobe-long_name
	......
	libbpf: failed to add legacy kprobe event for 'bpf_testmod_looooooooooooooooooooooooooooooong_name+0x0': -EINVAL
	libbpf: prog 'handle_kprobe': failed to create kprobe 'bpf_testmod_looooooooooooooooooooooooooooooong_name+0x0' perf event: -EINVAL
	test_attach_kprobe_long_event_name:FAIL:attach_kprobe_long_event_name unexpected error: -22
	test_attach_probe:PASS:uprobe_ref_ctr_cleanup 0 nsec
	#13/11   attach_probe/kprobe-long_name:FAIL
	#13      attach_probe:FAIL

	./test_progs -t attach_probe/uprobe-long_name
	......
	libbpf: failed to add legacy uprobe event for /root/linux-bpf/bpf-next/tools/testing/selftests/bpf/test_progs:0x13efd9: -EINVAL
	libbpf: prog 'handle_uprobe': failed to create uprobe '/root/linux-bpf/bpf-next/tools/testing/selftests/bpf/test_progs:0x13efd9' perf event: -EINVAL
	test_attach_uprobe_long_event_name:FAIL:attach_uprobe_long_event_name unexpected error: -22
	#13/10   attach_probe/uprobe-long_name:FAIL
	#13      attach_probe:FAIL
After Fix:
	./test_progs -t attach_probe/uprobe-long_name
	#13/10   attach_probe/uprobe-long_name:OK
	#13      attach_probe:OK
	Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED

	./test_progs -t attach_probe/kprobe-long_name
	#13/11   attach_probe/kprobe-long_name:OK
	#13      attach_probe:OK
	Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED

Fixes: 46ed5fc33db9 ("libbpf: Refactor and simplify legacy kprobe code")
Fixes: cc10623c6810 ("libbpf: Add legacy uprobe attaching support")
Signed-off-by: Hengqi Chen &lt;hengqi.chen@gmail.com&gt;
Signed-off-by: Feng Yang &lt;yangfeng@kylinos.cn&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250417014848.59321-2-yangfeng59949@163.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>libbpf: Fix buffer overflow in bpf_object__init_prog</title>
<updated>2025-06-19T13:39:42+00:00</updated>
<author>
<name>Viktor Malik</name>
<email>vmalik@redhat.com</email>
</author>
<published>2025-04-15T15:50:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0e84dc981b3b84553d7a1616e912e03153d82ac3'/>
<id>0e84dc981b3b84553d7a1616e912e03153d82ac3</id>
<content type='text'>
[ Upstream commit ee684de5c1b0ac01821320826baec7da93f3615b ]

As shown in [1], it is possible to corrupt a BPF ELF file such that
arbitrary BPF instructions are loaded by libbpf. This can be done by
setting a symbol (BPF program) section offset to a large (unsigned)
number such that &lt;section start + symbol offset&gt; overflows and points
before the section data in the memory.

Consider the situation below where:
- prog_start = sec_start + symbol_offset    &lt;-- size_t overflow here
- prog_end   = prog_start + prog_size

    prog_start        sec_start        prog_end        sec_end
        |                |                 |              |
        v                v                 v              v
    .....................|################################|............

The report in [1] also provides a corrupted BPF ELF which can be used as
a reproducer:

    $ readelf -S crash
    Section Headers:
      [Nr] Name              Type             Address           Offset
           Size              EntSize          Flags  Link  Info  Align
    ...
      [ 2] uretprobe.mu[...] PROGBITS         0000000000000000  00000040
           0000000000000068  0000000000000000  AX       0     0     8

    $ readelf -s crash
    Symbol table '.symtab' contains 8 entries:
       Num:    Value          Size Type    Bind   Vis      Ndx Name
    ...
         6: ffffffffffffffb8   104 FUNC    GLOBAL DEFAULT    2 handle_tp

Here, the handle_tp prog has section offset ffffffffffffffb8, i.e. will
point before the actual memory where section 2 is allocated.

This is also reported by AddressSanitizer:

    =================================================================
    ==1232==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x7c7302fe0000 at pc 0x7fc3046e4b77 bp 0x7ffe64677cd0 sp 0x7ffe64677490
    READ of size 104 at 0x7c7302fe0000 thread T0
        #0 0x7fc3046e4b76 in memcpy (/lib64/libasan.so.8+0xe4b76)
        #1 0x00000040df3e in bpf_object__init_prog /src/libbpf/src/libbpf.c:856
        #2 0x00000040df3e in bpf_object__add_programs /src/libbpf/src/libbpf.c:928
        #3 0x00000040df3e in bpf_object__elf_collect /src/libbpf/src/libbpf.c:3930
        #4 0x00000040df3e in bpf_object_open /src/libbpf/src/libbpf.c:8067
        #5 0x00000040f176 in bpf_object__open_file /src/libbpf/src/libbpf.c:8090
        #6 0x000000400c16 in main /poc/poc.c:8
        #7 0x7fc3043d25b4 in __libc_start_call_main (/lib64/libc.so.6+0x35b4)
        #8 0x7fc3043d2667 in __libc_start_main@@GLIBC_2.34 (/lib64/libc.so.6+0x3667)
        #9 0x000000400b34 in _start (/poc/poc+0x400b34)

    0x7c7302fe0000 is located 64 bytes before 104-byte region [0x7c7302fe0040,0x7c7302fe00a8)
    allocated by thread T0 here:
        #0 0x7fc3046e716b in malloc (/lib64/libasan.so.8+0xe716b)
        #1 0x7fc3045ee600 in __libelf_set_rawdata_wrlock (/lib64/libelf.so.1+0xb600)
        #2 0x7fc3045ef018 in __elf_getdata_rdlock (/lib64/libelf.so.1+0xc018)
        #3 0x00000040642f in elf_sec_data /src/libbpf/src/libbpf.c:3740

The problem here is that currently, libbpf only checks that the program
end is within the section bounds. There used to be a check
`while (sec_off &lt; sec_sz)` in bpf_object__add_programs, however, it was
removed by commit 6245947c1b3c ("libbpf: Allow gaps in BPF program
sections to support overriden weak functions").

Add a check for detecting the overflow of `sec_off + prog_sz` to
bpf_object__init_prog to fix this issue.

[1] https://github.com/lmarch2/poc/blob/main/libbpf/libbpf.md

Fixes: 6245947c1b3c ("libbpf: Allow gaps in BPF program sections to support overriden weak functions")
Reported-by: lmarch2 &lt;2524158037@qq.com&gt;
Signed-off-by: Viktor Malik &lt;vmalik@redhat.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Reviewed-by: Shung-Hsi Yu &lt;shung-hsi.yu@suse.com&gt;
Link: https://github.com/lmarch2/poc/blob/main/libbpf/libbpf.md
Link: https://lore.kernel.org/bpf/20250415155014.397603-1-vmalik@redhat.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 ee684de5c1b0ac01821320826baec7da93f3615b ]

As shown in [1], it is possible to corrupt a BPF ELF file such that
arbitrary BPF instructions are loaded by libbpf. This can be done by
setting a symbol (BPF program) section offset to a large (unsigned)
number such that &lt;section start + symbol offset&gt; overflows and points
before the section data in the memory.

Consider the situation below where:
- prog_start = sec_start + symbol_offset    &lt;-- size_t overflow here
- prog_end   = prog_start + prog_size

    prog_start        sec_start        prog_end        sec_end
        |                |                 |              |
        v                v                 v              v
    .....................|################################|............

The report in [1] also provides a corrupted BPF ELF which can be used as
a reproducer:

    $ readelf -S crash
    Section Headers:
      [Nr] Name              Type             Address           Offset
           Size              EntSize          Flags  Link  Info  Align
    ...
      [ 2] uretprobe.mu[...] PROGBITS         0000000000000000  00000040
           0000000000000068  0000000000000000  AX       0     0     8

    $ readelf -s crash
    Symbol table '.symtab' contains 8 entries:
       Num:    Value          Size Type    Bind   Vis      Ndx Name
    ...
         6: ffffffffffffffb8   104 FUNC    GLOBAL DEFAULT    2 handle_tp

Here, the handle_tp prog has section offset ffffffffffffffb8, i.e. will
point before the actual memory where section 2 is allocated.

This is also reported by AddressSanitizer:

    =================================================================
    ==1232==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x7c7302fe0000 at pc 0x7fc3046e4b77 bp 0x7ffe64677cd0 sp 0x7ffe64677490
    READ of size 104 at 0x7c7302fe0000 thread T0
        #0 0x7fc3046e4b76 in memcpy (/lib64/libasan.so.8+0xe4b76)
        #1 0x00000040df3e in bpf_object__init_prog /src/libbpf/src/libbpf.c:856
        #2 0x00000040df3e in bpf_object__add_programs /src/libbpf/src/libbpf.c:928
        #3 0x00000040df3e in bpf_object__elf_collect /src/libbpf/src/libbpf.c:3930
        #4 0x00000040df3e in bpf_object_open /src/libbpf/src/libbpf.c:8067
        #5 0x00000040f176 in bpf_object__open_file /src/libbpf/src/libbpf.c:8090
        #6 0x000000400c16 in main /poc/poc.c:8
        #7 0x7fc3043d25b4 in __libc_start_call_main (/lib64/libc.so.6+0x35b4)
        #8 0x7fc3043d2667 in __libc_start_main@@GLIBC_2.34 (/lib64/libc.so.6+0x3667)
        #9 0x000000400b34 in _start (/poc/poc+0x400b34)

    0x7c7302fe0000 is located 64 bytes before 104-byte region [0x7c7302fe0040,0x7c7302fe00a8)
    allocated by thread T0 here:
        #0 0x7fc3046e716b in malloc (/lib64/libasan.so.8+0xe716b)
        #1 0x7fc3045ee600 in __libelf_set_rawdata_wrlock (/lib64/libelf.so.1+0xb600)
        #2 0x7fc3045ef018 in __elf_getdata_rdlock (/lib64/libelf.so.1+0xc018)
        #3 0x00000040642f in elf_sec_data /src/libbpf/src/libbpf.c:3740

The problem here is that currently, libbpf only checks that the program
end is within the section bounds. There used to be a check
`while (sec_off &lt; sec_sz)` in bpf_object__add_programs, however, it was
removed by commit 6245947c1b3c ("libbpf: Allow gaps in BPF program
sections to support overriden weak functions").

Add a check for detecting the overflow of `sec_off + prog_sz` to
bpf_object__init_prog to fix this issue.

[1] https://github.com/lmarch2/poc/blob/main/libbpf/libbpf.md

Fixes: 6245947c1b3c ("libbpf: Allow gaps in BPF program sections to support overriden weak functions")
Reported-by: lmarch2 &lt;2524158037@qq.com&gt;
Signed-off-by: Viktor Malik &lt;vmalik@redhat.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Reviewed-by: Shung-Hsi Yu &lt;shung-hsi.yu@suse.com&gt;
Link: https://github.com/lmarch2/poc/blob/main/libbpf/libbpf.md
Link: https://lore.kernel.org/bpf/20250415155014.397603-1-vmalik@redhat.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>libbpf: Fix implicit memfd_create() for bionic</title>
<updated>2025-06-19T13:39:38+00:00</updated>
<author>
<name>Carlos Llamas</name>
<email>cmllamas@google.com</email>
</author>
<published>2025-03-30T21:13:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=94c2cccad82b870b87a6c9735cc85a4f1818706a'/>
<id>94c2cccad82b870b87a6c9735cc85a4f1818706a</id>
<content type='text'>
[ Upstream commit 75011ad69bc54396703867b5434f1622343a848e ]

Since memfd_create() is not consistently available across different
bionic libc implementations, using memfd_create() directly can break
some Android builds:

  tools/lib/bpf/linker.c:576:7: error: implicit declaration of function 'memfd_create' [-Werror,-Wimplicit-function-declaration]
    576 |         fd = memfd_create(filename, 0);
        |              ^

To fix this, relocate and inline the sys_memfd_create() helper so that
it can be used in "linker.c". Similar issues were previously fixed by
commit 9fa5e1a180aa ("libbpf: Call memfd_create() syscall directly").

Fixes: 6d5e5e5d7ce1 ("libbpf: Extend linker API to support in-memory ELF files")
Signed-off-by: Carlos Llamas &lt;cmllamas@google.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250330211325.530677-1-cmllamas@google.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 75011ad69bc54396703867b5434f1622343a848e ]

Since memfd_create() is not consistently available across different
bionic libc implementations, using memfd_create() directly can break
some Android builds:

  tools/lib/bpf/linker.c:576:7: error: implicit declaration of function 'memfd_create' [-Werror,-Wimplicit-function-declaration]
    576 |         fd = memfd_create(filename, 0);
        |              ^

To fix this, relocate and inline the sys_memfd_create() helper so that
it can be used in "linker.c". Similar issues were previously fixed by
commit 9fa5e1a180aa ("libbpf: Call memfd_create() syscall directly").

Fixes: 6d5e5e5d7ce1 ("libbpf: Extend linker API to support in-memory ELF files")
Signed-off-by: Carlos Llamas &lt;cmllamas@google.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250330211325.530677-1-cmllamas@google.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Fix in-source libperf build</title>
<updated>2025-04-29T19:32:31+00:00</updated>
<author>
<name>James Clark</name>
<email>james.clark@linaro.org</email>
</author>
<published>2025-04-29T14:22:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8988c4b91945173a6b5505764915d470f0238fdc'/>
<id>8988c4b91945173a6b5505764915d470f0238fdc</id>
<content type='text'>
When libperf is built alone in-source, $(OUTPUT) isn't set. This causes
the generated uapi path to resolve to '/../arch' which results in a
permissions error:

  mkdir: cannot create directory '/../arch': Permission denied

Fix it by removing the preceding '/..' which means that it gets
generated either in the tools/lib/perf part of the tree or the OUTPUT
folder. Some other rules that rely on OUTPUT further refine this
conditionally depending on whether it's an in-source or out-of-source
build, but I don't think we need the extra complexity here. And this
rule is slightly different to others because the header is needed by
both libperf and Perf. This is further complicated by the fact that Perf
always passes O=... to libperf even for in source builds, meaning that
OUTPUT isn't set consistently between projects.

Because we're no longer going one level up to try to generate the file
in the tools/ folder, Perf's include rule needs to descend into libperf.
Also fix the clean rule while we're here.

Reported-by: Thorsten Leemhuis &lt;linux@leemhuis.info&gt;
Closes: https://lore.kernel.org/linux-perf-users/7703f88e-ccb7-4c98-9da4-8aad224e780f@leemhuis.info/
Fixes: bfb713ea53c7 ("perf tools: Fix arm64 build by generating unistd_64.h")
Signed-off-by: James Clark &lt;james.clark@linaro.org&gt;
Tested-by: Thorsten Leemhuis &lt;linux@leemhuis.info&gt;
Link: https://lore.kernel.org/r/20250429-james-perf-fix-libperf-in-source-build-v1-1-a1a827ac15e5@linaro.org
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When libperf is built alone in-source, $(OUTPUT) isn't set. This causes
the generated uapi path to resolve to '/../arch' which results in a
permissions error:

  mkdir: cannot create directory '/../arch': Permission denied

Fix it by removing the preceding '/..' which means that it gets
generated either in the tools/lib/perf part of the tree or the OUTPUT
folder. Some other rules that rely on OUTPUT further refine this
conditionally depending on whether it's an in-source or out-of-source
build, but I don't think we need the extra complexity here. And this
rule is slightly different to others because the header is needed by
both libperf and Perf. This is further complicated by the fact that Perf
always passes O=... to libperf even for in source builds, meaning that
OUTPUT isn't set consistently between projects.

Because we're no longer going one level up to try to generate the file
in the tools/ folder, Perf's include rule needs to descend into libperf.
Also fix the clean rule while we're here.

Reported-by: Thorsten Leemhuis &lt;linux@leemhuis.info&gt;
Closes: https://lore.kernel.org/linux-perf-users/7703f88e-ccb7-4c98-9da4-8aad224e780f@leemhuis.info/
Fixes: bfb713ea53c7 ("perf tools: Fix arm64 build by generating unistd_64.h")
Signed-off-by: James Clark &lt;james.clark@linaro.org&gt;
Tested-by: Thorsten Leemhuis &lt;linux@leemhuis.info&gt;
Link: https://lore.kernel.org/r/20250429-james-perf-fix-libperf-in-source-build-v1-1-a1a827ac15e5@linaro.org
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Fix arm64 build by generating unistd_64.h</title>
<updated>2025-04-23T15:57:12+00:00</updated>
<author>
<name>James Clark</name>
<email>james.clark@linaro.org</email>
</author>
<published>2025-04-17T13:55:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bfb713ea53c746b07ae69fe97fa9b5388e4f34f9'/>
<id>bfb713ea53c746b07ae69fe97fa9b5388e4f34f9</id>
<content type='text'>
Since pulling in the kernel changes in commit 22f72088ffe6 ("tools
headers: Update the syscall table with the kernel sources"), arm64 is
no longer using a generic syscall header and generates one from the
syscall table. Therefore we must also generate the syscall header for
arm64 before building Perf.

Add it as a dependency to libperf which uses one syscall number. Perf
uses more, but as libperf is a dependency of Perf it will be generated
for both.

Future platforms that need this will have to add their own syscall-y
targets in libperf manually. Unfortunately the arch specific files that
do this (e.g. arch/arm64/include/asm/Kbuild) can't easily be imported
into the Perf build. But Perf only needs a subset of the generated files
anyway, so redefining them is probably the correct thing to do.

Fixes: 22f72088ffe6 ("tools headers: Update the syscall table with the kernel sources")
Signed-off-by: James Clark &lt;james.clark@linaro.org&gt;
Tested-by: Harshit Mogalapalli &lt;harshit.m.mogalapalli@oracle.com&gt;
Link: https://lore.kernel.org/r/20250417-james-perf-fix-gen-syscall-v1-1-1d268c923901@linaro.org
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Since pulling in the kernel changes in commit 22f72088ffe6 ("tools
headers: Update the syscall table with the kernel sources"), arm64 is
no longer using a generic syscall header and generates one from the
syscall table. Therefore we must also generate the syscall header for
arm64 before building Perf.

Add it as a dependency to libperf which uses one syscall number. Perf
uses more, but as libperf is a dependency of Perf it will be generated
for both.

Future platforms that need this will have to add their own syscall-y
targets in libperf manually. Unfortunately the arch specific files that
do this (e.g. arch/arm64/include/asm/Kbuild) can't easily be imported
into the Perf build. But Perf only needs a subset of the generated files
anyway, so redefining them is probably the correct thing to do.

Fixes: 22f72088ffe6 ("tools headers: Update the syscall table with the kernel sources")
Signed-off-by: James Clark &lt;james.clark@linaro.org&gt;
Tested-by: Harshit Mogalapalli &lt;harshit.m.mogalapalli@oracle.com&gt;
Link: https://lore.kernel.org/r/20250417-james-perf-fix-gen-syscall-v1-1-1d268c923901@linaro.org
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
