[LTP] [PATCH] read_all: Fix buffer too small for long paths

[LTP] [PATCH] read_all: Fix buffer too small for long paths

[Michael Menasherov via ltp]

queue_pop() copies each path into popped[BUFFER_SIZE], but BUFFER_SIZE
was 1024 while visit_dir() builds paths up to MAX_PATH (4096). Any path
longer than 1023 bytes aborted the test with TBROK "Buffer is too small
for path".

Set BUFFER_SIZE to 4096 to match MAX_PATH. QUEUE_SIZE (16384) still
holds a full-length path.

Tested on smaller boards and then on local machines with deeply nested
directories under /sys; read_all_sys now passes instead of aborting.

Fixes: 67c95fbbfc3a ("Add read_all file systems test")
Signed-off-by: Michael Menasherov <mmenashe@redhat.com>
---
 testcases/kernel/fs/read_all/read_all.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/testcases/kernel/fs/read_all/read_all.c b/testcases/kernel/fs/read_all/read_all.c
index 5720ffb99..d67fe5712 100644
--- a/testcases/kernel/fs/read_all/read_all.c
+++ b/testcases/kernel/fs/read_all/read_all.c
@@ -51,7 +51,7 @@
 #include "tst_timer.h"
 
 #define QUEUE_SIZE 16384
-#define BUFFER_SIZE 1024
+#define BUFFER_SIZE 4096
 #define MAX_PATH 4096
 #define MAX_DISPLAY 40
 
-- 
2.55.0


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Re: [LTP] read_all: Fix buffer too small for long paths

[linuxtestproject.agent]

Hi Michael,

On Sun, 06 Sep 2026 16:56:50 +0300, Michael Menasherov wrote:
> read_all: Fix buffer too small for long paths

> -#define BUFFER_SIZE 1024
> +#define BUFFER_SIZE 4096

queue_pop() still aborts for a 4095-byte pathname: after copying its final
byte, ++j is 4095, which satisfies BUFFER_SIZE - 1. Use PATH_MAX for popped
and compare j against PATH_MAX so every pathname that fits dent_path also
fits the queue buffer.

Verdict - Needs revision

Pre-existing issue:

read_all.c:218 has an unnecessary blank line before a closing brace, as
reported by make check.

---
Note:

The agent can sometimes produce false positives although often its
findings are genuine. If you find issues with the review, please
comment this email or ignore the suggestions.

Regards,
LTP AI Reviewer

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Re: [LTP] [PATCH] read_all: Fix buffer too small for long paths

[Andrea Cervesato via ltp]

Hi Michael,

>  #define QUEUE_SIZE 16384
> -#define BUFFER_SIZE 1024
> +#define BUFFER_SIZE 4096

better to use PATH_MAX here and make sure that when we create a path,
PATH_MAX is always preserved as the maximum size of the strings.

--
Andrea Cervesato
SUSE QE Automation Engineer Linux
andrea.cervesato@suse.com

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Re: [LTP] read_all: Fix buffer too small for long paths

[linuxtestproject.agent]

Hi Michael,

On Sep 7, 2026, Michael Menasherov wrote:
> read_all: Fix buffer too small for long paths

> +#define BUFFER_SIZE PATH_MAX

With the existing `if (++j >= BUFFER_SIZE - 1)` check, this still rejects a
valid PATH_MAX - 1-character pathname and reports TBROK before writing its
terminating NUL. A 4095-byte pathname reproduces this on PATH_MAX=4096; change
the queue_pop() bound so PATH_MAX - 1 characters fit.

Verdict - Needs revision

---
Note:

The agent can sometimes produce false positives although often its
findings are genuine. If you find issues with the review, please
comment this email or ignore the suggestions.

Regards,
LTP AI Reviewer

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Re: [LTP] read_all: Fix buffer too small for long paths

[linuxtestproject.agent]

Hi Michael,

On Tue Sep 8 12:22:48 2026 +0300, Michael Menasherov via ltp wrote:
> read_all: Fix buffer too small for long paths

Verdict - Reviewed

---
Note:

The agent can sometimes produce false positives although often its
findings are genuine. If you find issues with the review, please
comment this email or ignore the suggestions.

Regards,
LTP AI Reviewer

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