orangefs_prepare_debugfs_help_string() constructs the debugfs help text in a dynamically allocated buffer using repeated strlcat() calls across keyword loops, rescanning the buffer on every append. In preparation for removing the deprecated strlcat() API[1], use struct seq_buf to build the help string. This tracks the write position across the loops, allows formatting each keyword line with a single seq_buf_printf() call, and checks for truncation via seq_buf_has_overflowed(). Additionally, replace the final strlcat() call that copies the completed string into debug_help_string with strscpy(). Link: https://github.com/KSPP/linux/issues/370 [1] Cc: codemender-patching+linux@google.com Assisted-by: Gemini:gemini-2.0-flash-exp [shell_command_run, editor_update_file] Signed-off-by: Bill Wendling --- Cc: Russell King Cc: Huacai Chen Cc: WANG Xuerui Cc: Thomas Bogendoerfer Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: x86@kernel.org Cc: "H. Peter Anvin" Cc: Ian Abbott Cc: H Hartley Sweeten Cc: Tony Luck Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Thomas Zimmermann Cc: David Airlie Cc: Simona Vetter Cc: Matthew Brost Cc: "Thomas Hellström" Cc: Rodrigo Vivi Cc: Dmitry Torokhov Cc: Matthias Schwarzott Cc: Mauro Carvalho Chehab Cc: Tony Nguyen Cc: Przemek Kitszel Cc: Andrew Lunn Cc: "David S. Miller" Cc: Eric Dumazet Cc: Jakub Kicinski Cc: Paolo Abeni Cc: Arend van Spriel Cc: Rob Herring Cc: Saravana Kannan Cc: Krzysztof Kozlowski Cc: Sylwester Nawrocki Cc: Peter Griffin Cc: Alim Akhtar Cc: Linus Walleij Cc: Anil Gurumurthy Cc: Sudarsana Kalluru Cc: "Martin K. Petersen" Cc: Trond Myklebust Cc: Anna Schumaker Cc: Mike Marshall Cc: Martin Brandenburg Cc: Kees Cook Cc: Jiri Pirko Cc: Simon Horman Cc: Chuck Lever Cc: Jeff Layton Cc: NeilBrown Cc: Olga Kornievskaia Cc: Dai Ngo Cc: Tom Talpey Cc: Jaroslav Kysela Cc: Takashi Iwai Cc: Bill Wendling Cc: Andrew Morton Cc: "Mike Rapoport (Microsoft)" Cc: Kanglong Wang Cc: Tiezhu Yang Cc: Qiang Ma Cc: Randy Dunlap Cc: Pengpeng Hou Cc: Ard Biesheuvel Cc: Breno Leitao Cc: Thorsten Blum Cc: Harshit Mogalapalli Cc: Greg Kroah-Hartman Cc: Lyude Paul Cc: Ashutosh Desai Cc: Imre Deak Cc: Dmitry Baryshkov Cc: Johan Hovold Cc: Johannes Berg Cc: Miri Korenblit Cc: Alexander Stein Cc: Cryolitia PukNgae Cc: Jiaming Zhang Cc: Will Porter Cc: Cen Zhang Cc: "Cássio Gabriel" Cc: Rong Zhang Cc: Arun Raghavan Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: loongarch@lists.linux.dev Cc: linux-mips@vger.kernel.org Cc: linux-parisc@vger.kernel.org Cc: linux-edac@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: intel-xe@lists.freedesktop.org Cc: linux-input@vger.kernel.org Cc: linux-media@vger.kernel.org Cc: intel-wired-lan@lists.osuosl.org Cc: netdev@vger.kernel.org Cc: linux-wireless@vger.kernel.org Cc: brcm80211@lists.linux.dev Cc: brcm80211-dev-list.pdl@broadcom.com Cc: devicetree@vger.kernel.org Cc: linux-samsung-soc@vger.kernel.org Cc: linux-gpio@vger.kernel.org Cc: linux-scsi@vger.kernel.org Cc: linux-nfs@vger.kernel.org Cc: devel@lists.orangefs.org Cc: linux-hardening@vger.kernel.org Cc: linux-sound@vger.kernel.org --- fs/orangefs/orangefs-debugfs.c | 36 +++++++++++++--------------------- 1 file changed, 14 insertions(+), 22 deletions(-) diff --git a/fs/orangefs/orangefs-debugfs.c b/fs/orangefs/orangefs-debugfs.c index 9f94919a6bc6..6e2f9887eab4 100644 --- a/fs/orangefs/orangefs-debugfs.c +++ b/fs/orangefs/orangefs-debugfs.c @@ -37,6 +37,7 @@ */ #include #include +#include #include @@ -623,10 +624,10 @@ int orangefs_prepare_debugfs_help_string(int at_boot) char *client_title = "Client Debug Keywords:\n"; char *kernel_title = "Kernel Debug Keywords:\n"; size_t string_size = DEBUG_HELP_STRING_SIZE; - size_t result_size; size_t i; char *new; int rc = -EINVAL; + struct seq_buf s; gossip_debug(GOSSIP_UTILS_DEBUG, "%s: start\n", __func__); @@ -640,17 +641,14 @@ int orangefs_prepare_debugfs_help_string(int at_boot) goto out; } + seq_buf_init(&s, new, string_size); + /* - * strlcat(dst, src, size) will append at most - * "size - strlen(dst) - 1" bytes of src onto dst, - * null terminating the result, and return the total - * length of the string it tried to create. - * * We'll just plow through here building our new debug - * help string and let strlcat take care of assuring that + * help string and let seq_buf take care of assuring that * dst doesn't overflow. */ - strlcat(new, client_title, string_size); + seq_buf_puts(&s, client_title); if (!at_boot) { @@ -665,24 +663,18 @@ int orangefs_prepare_debugfs_help_string(int at_boot) goto out; } - for (i = 0; i < cdm_element_count; i++) { - strlcat(new, "\t", string_size); - strlcat(new, cdm_array[i].keyword, string_size); - strlcat(new, "\n", string_size); - } + for (i = 0; i < cdm_element_count; i++) + seq_buf_printf(&s, "\t%s\n", cdm_array[i].keyword); } - strlcat(new, "\n", string_size); - strlcat(new, kernel_title, string_size); + seq_buf_puts(&s, "\n"); + seq_buf_puts(&s, kernel_title); - for (i = 0; i < num_kmod_keyword_mask_map; i++) { - strlcat(new, "\t", string_size); - strlcat(new, s_kmod_keyword_mask_map[i].keyword, string_size); - result_size = strlcat(new, "\n", string_size); - } + for (i = 0; i < num_kmod_keyword_mask_map; i++) + seq_buf_printf(&s, "\t%s\n", s_kmod_keyword_mask_map[i].keyword); /* See if we tried to put too many bytes into "new"... */ - if (result_size >= string_size) { + if (seq_buf_has_overflowed(&s)) { kfree(new); goto out; } @@ -692,7 +684,7 @@ int orangefs_prepare_debugfs_help_string(int at_boot) } else { mutex_lock(&orangefs_help_file_lock); memset(debug_help_string, 0, DEBUG_HELP_STRING_SIZE); - strlcat(debug_help_string, new, string_size); + strscpy(debug_help_string, new, DEBUG_HELP_STRING_SIZE); mutex_unlock(&orangefs_help_file_lock); kfree(new); } -- 2.55.0.1032.g73a4cd73de-goog