From fb2475e6bd5dc8cc5cd50c8941d75d9932a15579 Mon Sep 17 00:00:00 2001 From: Daniel Golle Date: Fri, 3 May 2024 21:27:37 +0100 Subject: [PATCH] generic: 6.6: fix and simplify blkdevparts= cmdline parsing Import pending patch to fix the cmdline parsing of the "blkdevparts=" parameter which has been broken somewhen between Linux 6.1 and Linux 6.6. Signed-off-by: Daniel Golle --- ...simplify-blkdevparts-cmdline-parsing.patch | 217 ++++++++++++++++++ 1 file changed, 217 insertions(+) create mode 100644 target/linux/generic/pending-6.6/195-block-fix-and-simplify-blkdevparts-cmdline-parsing.patch diff --git a/target/linux/generic/pending-6.6/195-block-fix-and-simplify-blkdevparts-cmdline-parsing.patch b/target/linux/generic/pending-6.6/195-block-fix-and-simplify-blkdevparts-cmdline-parsing.patch new file mode 100644 index 000000000000..d504a74fdecd --- /dev/null +++ b/target/linux/generic/pending-6.6/195-block-fix-and-simplify-blkdevparts-cmdline-parsing.patch @@ -0,0 +1,217 @@ +From patchwork Sun Apr 21 07:39:52 2024 +Content-Type: text/plain; charset="utf-8" +MIME-Version: 1.0 +Content-Transfer-Encoding: 7bit +X-Patchwork-Submitter: INAGAKI Hiroshi +X-Patchwork-Id: 13637306 +From: INAGAKI Hiroshi +To: axboe@kernel.dk +Cc: yang.yang29@zte.com, + justinstitt@google.com, + xu.panda@zte.com.cn, + linux-block@vger.kernel.org, + linux-kernel@vger.kernel.org, + INAGAKI Hiroshi , + Naohiro Aota +Subject: [PATCH] block: fix and simplify blkdevparts= cmdline parsing +Date: Sun, 21 Apr 2024 16:39:52 +0900 +Message-ID: <20240421074005.565-1-musashino.open@gmail.com> +X-Mailer: git-send-email 2.42.0.windows.2 +Precedence: bulk +X-Mailing-List: linux-block@vger.kernel.org +List-Id: +List-Subscribe: +List-Unsubscribe: +MIME-Version: 1.0 + +Fix the cmdline parsing of the "blkdevparts=" parameter using strsep(), +which makes the code simpler. + +Before commit 146afeb235cc ("block: use strscpy() to instead of +strncpy()"), we used a strncpy() to copy a block device name and partition +names. The commit simply replaced a strncpy() and NULL termination with +a strscpy(). It did not update calculations of length passed to strscpy(). +While the length passed to strncpy() is just a length of valid characters +without NULL termination ('\0'), strscpy() takes it as a length of the +destination buffer, including a NULL termination. + +Since the source buffer is not necessarily NULL terminated, the current +code copies "length - 1" characters and puts a NULL character in the +destination buffer. It replaces the last character with NULL and breaks +the parsing. + +As an example, that buffer will be passed to parse_parts() and breaks +parsing sub-partitions due to the missing ')' at the end, like the +following. + +example (Check Point V-80 & OpenWrt): + +- Linux Kernel 6.6 + + [ 0.000000] Kernel command line: console=ttyS0,115200 earlycon=uart8250,mmio32,0xf0512000 crashkernel=30M mvpp2x.queue_mode=1 blkdevparts=mmcblk1:48M@10M(kernel-1),1M(dtb-1),720M(rootfs-1),48M(kernel-2),1M(dtb-2),720M(rootfs-2),300M(default_sw),650M(logs),1M(preset_cfg),1M(adsl),-(storage) maxcpus=4 + ... + [ 0.884016] mmc1: new HS200 MMC card at address 0001 + [ 0.889951] mmcblk1: mmc1:0001 004GA0 3.69 GiB + [ 0.895043] cmdline partition format is invalid. + [ 0.895704] mmcblk1: p1 + [ 0.903447] mmcblk1boot0: mmc1:0001 004GA0 2.00 MiB + [ 0.908667] mmcblk1boot1: mmc1:0001 004GA0 2.00 MiB + [ 0.913765] mmcblk1rpmb: mmc1:0001 004GA0 512 KiB, chardev (248:0) + + 1. "48M@10M(kernel-1),..." is passed to strscpy() with length=17 + from parse_parts() + 2. strscpy() returns -E2BIG and the destination buffer has + "48M@10M(kernel-1\0" + 3. "48M@10M(kernel-1\0" is passed to parse_subpart() + 4. parse_subpart() fails to find ')' when parsing a partition name, + and returns error + +- Linux Kernel 6.1 + + [ 0.000000] Kernel command line: console=ttyS0,115200 earlycon=uart8250,mmio32,0xf0512000 crashkernel=30M mvpp2x.queue_mode=1 blkdevparts=mmcblk1:48M@10M(kernel-1),1M(dtb-1),720M(rootfs-1),48M(kernel-2),1M(dtb-2),720M(rootfs-2),300M(default_sw),650M(logs),1M(preset_cfg),1M(adsl),-(storage) maxcpus=4 + ... + [ 0.953142] mmc1: new HS200 MMC card at address 0001 + [ 0.959114] mmcblk1: mmc1:0001 004GA0 3.69 GiB + [ 0.964259] mmcblk1: p1(kernel-1) p2(dtb-1) p3(rootfs-1) p4(kernel-2) p5(dtb-2) 6(rootfs-2) p7(default_sw) p8(logs) p9(preset_cfg) p10(adsl) p11(storage) + [ 0.979174] mmcblk1boot0: mmc1:0001 004GA0 2.00 MiB + [ 0.984674] mmcblk1boot1: mmc1:0001 004GA0 2.00 MiB + [ 0.989926] mmcblk1rpmb: mmc1:0001 004GA0 512 KiB, chardev (248:0 + +By the way, strscpy() takes a length of destination buffer and it is +often confusing when copying characters with a specified length. Using +strsep() helps to separate the string by the specified character. Then, +we can use strscpy() naturally with the size of the destination buffer. + +Separating the string on the fly is also useful to omit the redundant +string copy, reducing memory usage and improve the code readability. + +Fixes: 146afeb235cc ("block: use strscpy() to instead of strncpy()") +Suggested-by: Naohiro Aota +Signed-off-by: INAGAKI Hiroshi +Reviewed-by: Daniel Golle +--- + block/partitions/cmdline.c | 49 ++++++++++---------------------------- + 1 file changed, 12 insertions(+), 37 deletions(-) + +--- a/block/partitions/cmdline.c ++++ b/block/partitions/cmdline.c +@@ -70,8 +70,8 @@ static int parse_subpart(struct cmdline_ + } + + if (*partdef == '(') { +- int length; +- char *next = strchr(++partdef, ')'); ++ partdef++; ++ char *next = strsep(&partdef, ")"); + + if (!next) { + pr_warn("cmdline partition format is invalid."); +@@ -79,11 +79,7 @@ static int parse_subpart(struct cmdline_ + goto fail; + } + +- length = min_t(int, next - partdef, +- sizeof(new_subpart->name) - 1); +- strscpy(new_subpart->name, partdef, length); +- +- partdef = ++next; ++ strscpy(new_subpart->name, next, sizeof(new_subpart->name)); + } else + new_subpart->name[0] = '\0'; + +@@ -117,14 +113,12 @@ static void free_subpart(struct cmdline_ + } + } + +-static int parse_parts(struct cmdline_parts **parts, const char *bdevdef) ++static int parse_parts(struct cmdline_parts **parts, char *bdevdef) + { + int ret = -EINVAL; + char *next; +- int length; + struct cmdline_subpart **next_subpart; + struct cmdline_parts *newparts; +- char buf[BDEVNAME_SIZE + 32 + 4]; + + *parts = NULL; + +@@ -132,28 +126,19 @@ static int parse_parts(struct cmdline_pa + if (!newparts) + return -ENOMEM; + +- next = strchr(bdevdef, ':'); ++ next = strsep(&bdevdef, ":"); + if (!next) { + pr_warn("cmdline partition has no block device."); + goto fail; + } + +- length = min_t(int, next - bdevdef, sizeof(newparts->name) - 1); +- strscpy(newparts->name, bdevdef, length); ++ strscpy(newparts->name, next, sizeof(newparts->name)); + newparts->nr_subparts = 0; + + next_subpart = &newparts->subpart; + +- while (next && *(++next)) { +- bdevdef = next; +- next = strchr(bdevdef, ','); +- +- length = (!next) ? (sizeof(buf) - 1) : +- min_t(int, next - bdevdef, sizeof(buf) - 1); +- +- strscpy(buf, bdevdef, length); +- +- ret = parse_subpart(next_subpart, buf); ++ while ((next = strsep(&bdevdef, ","))) { ++ ret = parse_subpart(next_subpart, next); + if (ret) + goto fail; + +@@ -199,24 +184,17 @@ static int cmdline_parts_parse(struct cm + + *parts = NULL; + +- next = pbuf = buf = kstrdup(cmdline, GFP_KERNEL); ++ pbuf = buf = kstrdup(cmdline, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + next_parts = parts; + +- while (next && *pbuf) { +- next = strchr(pbuf, ';'); +- if (next) +- *next = '\0'; +- +- ret = parse_parts(next_parts, pbuf); ++ while ((next = strsep(&pbuf, ";"))) { ++ ret = parse_parts(next_parts, next); + if (ret) + goto fail; + +- if (next) +- pbuf = ++next; +- + next_parts = &(*next_parts)->next_parts; + } + +@@ -250,7 +228,6 @@ static struct cmdline_parts *bdev_parts; + static int add_part(int slot, struct cmdline_subpart *subpart, + struct parsed_partitions *state) + { +- int label_min; + struct partition_meta_info *info; + char tmp[sizeof(info->volname) + 4]; + +@@ -262,9 +239,7 @@ static int add_part(int slot, struct cmd + + info = &state->parts[slot].info; + +- label_min = min_t(int, sizeof(info->volname) - 1, +- sizeof(subpart->name)); +- strscpy(info->volname, subpart->name, label_min); ++ strscpy(info->volname, subpart->name, sizeof(info->volname)); + + snprintf(tmp, sizeof(tmp), "(%s)", info->volname); + strlcat(state->pp_buf, tmp, PAGE_SIZE); -- 2.30.2