!160 cat/dd/split: don’t trust st_size on /proc files

From: @huyubiao 
Reviewed-by: @xujing99 
Signed-off-by: @xujing99

backport-cat-don-t-trust-st_size-on-proc-files.patch

@@ -0,0 +1,105 @@
+From 225cb8d7473eadb481a4884e929bf23589d4bd82 Mon Sep 17 00:00:00 2001
+From: Paul Eggert <eggert@cs.ucla.edu>
+Date: Sat, 6 Apr 2024 15:13:23 -0700
+Subject: [PATCH] =?UTF-8?q?cat:=20don=E2=80=99t=20trust=20st=5Fsize=20on?=
+ =?UTF-8?q?=20/proc=20files?=
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+* src/cat.c (main):
+Improve test for when copying will exhaust the output device.
+Do not rely on st_size, which is unreliable in /proc.
+Use lseek instead; this is good enough here.
+* tests/cat/cat-self.sh: Test the relaxation of the heuristic
+for self-copying.
+---
+ src/cat.c             | 31 +++++++++++++++++++++----------
+ tests/cat/cat-self.sh | 20 ++++++++++++++++++++
+ 2 files changed, 41 insertions(+), 10 deletions(-)
+
+diff --git a/src/cat.c b/src/cat.c
+index ac39a48..14e6dfd 100644
+--- a/src/cat.c
++++ b/src/cat.c
+@@ -646,9 +646,10 @@ main (int argc, char **argv)
+   /* Optimal size of i/o operations of output.  */
+   idx_t outsize = io_blksize (stat_buf);
+ 
+-  /* Device and I-node number of the output.  */
++  /* Device, I-node number and lazily-acquired flags of the output.  */
+   dev_t out_dev = stat_buf.st_dev;
+   ino_t out_ino = stat_buf.st_ino;
++  int out_flags = -2;
+ 
+   /* True if the output is a regular file.  */
+   bool out_isreg = S_ISREG (stat_buf.st_mode) != 0;
+@@ -702,17 +703,27 @@ main (int argc, char **argv)
+ 
+       fdadvise (input_desc, 0, 0, FADVISE_SEQUENTIAL);
+ 
+-      /* Don't copy a nonempty regular file to itself, as that would
+-         merely exhaust the output device.  It's better to catch this
+-         error earlier rather than later.  */
++      /* Don't copy a file to itself if that would merely exhaust the
++         output device.  It's better to catch this error earlier
++         rather than later.  */
+ 
+-      if (out_isreg
+-          && stat_buf.st_dev == out_dev && stat_buf.st_ino == out_ino
+-          && lseek (input_desc, 0, SEEK_CUR) < stat_buf.st_size)
++      if (stat_buf.st_dev == out_dev && stat_buf.st_ino == out_ino)
+         {
+-          error (0, 0, _("%s: input file is output file"), quotef (infile));
+-          ok = false;
+-          goto contin;
++          if (out_flags < -1)
++            out_flags = fcntl (STDOUT_FILENO, F_GETFL);
++          bool exhausting = 0 <= out_flags && out_flags & O_APPEND;
++          if (!exhausting)
++            {
++              off_t in_pos = lseek (input_desc, 0, SEEK_CUR);
++              if (0 <= in_pos)
++                exhausting = in_pos < lseek (STDOUT_FILENO, 0, SEEK_CUR);
++            }
++          if (exhausting)
++            {
++              error (0, 0, _("%s: input file is output file"), quotef (infile));
++              ok = false;
++              goto contin;
++            }
+         }
+ 
+       /* Pointer to the input buffer.  */
+diff --git a/tests/cat/cat-self.sh b/tests/cat/cat-self.sh
+index ff2afdc..f412707 100755
+--- a/tests/cat/cat-self.sh
++++ b/tests/cat/cat-self.sh
+@@ -30,4 +30,24 @@ echo y >doc.end || framework_failure_
+ cat doc doc.end >doc || fail=1
+ compare doc doc.end || fail=1
+ 
++# This terminates even though it copies a file to itself.
++# Coreutils 9.5 and earlier rejected this.
++echo x >fx || framework_failure_
++echo y >fy || framework_failure_
++cat fx fy >fxy || fail=1
++for i in 1 2; do
++  cat fx >fxy$i || fail=1
++done
++for i in 3 4 5 6; do
++  cat fx >fx$i || fail=1
++done
++cat - fy <fxy1 1<>fxy1 || fail=1
++compare fxy fxy1 || fail=1
++cat fxy2 fy 1<>fxy2 || fail=1
++compare fxy fxy2 || fail=1
++returns_ 1 cat fx fx3 1<>fx3 || fail=1
++returns_ 1 cat - fx4 <fx 1<>fx4 || fail=1
++returns_ 1 cat fx5 >>fx5 || fail=1
++returns_ 1 cat <fx6 >>fx6 || fail=1
++
+ Exit $fail
+-- 
+2.27.0
+

backport-dd-don-t-trust-st_size-on-proc-files.patch

@@ -0,0 +1,30 @@
+From ac6b8d8224de140f5a6f2ca66e6ce279604a37e6 Mon Sep 17 00:00:00 2001
+From: Paul Eggert <eggert@cs.ucla.edu>
+Date: Sat, 6 Apr 2024 15:15:04 -0700
+Subject: [PATCH] =?UTF-8?q?dd:=20don=E2=80=99t=20trust=20st=5Fsize=20on=20?=
+ =?UTF-8?q?/proc/files?=
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+* src/dd.c (skip): Don’t trust st_size == 0
+---
+ src/dd.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/src/dd.c b/src/dd.c
+index b50b841..a582111 100644
+--- a/src/dd.c
++++ b/src/dd.c
+@@ -1813,7 +1813,7 @@ skip (int fdesc, char const *file, intmax_t records, idx_t blocksize,
+            struct stat st;
+            if (ifstat (STDIN_FILENO, &st) != 0)
+              error (EXIT_FAILURE, errno, _("cannot fstat %s"), quoteaf (file));
+-           if (usable_st_size (&st) && 0 <= input_offset
++           if (usable_st_size (&st) && 0 < st.st_size && 0 <= input_offset
+                && st.st_size - input_offset < offset)
+              {
+                /* When skipping past EOF, return the number of _full_ blocks
+-- 
+2.27.0
+

backport-split-don-t-trust-st_size-on-proc-files.patch

@@ -0,0 +1,34 @@
+From 11163675818ab877f20d3740a7c3e59d565b8e9c Mon Sep 17 00:00:00 2001
+From: Paul Eggert <eggert@cs.ucla.edu>
+Date: Sat, 6 Apr 2024 15:18:04 -0700
+Subject: [PATCH] =?UTF-8?q?split:=20don=E2=80=99t=20trust=20st=5Fsize=20on?=
+ =?UTF-8?q?=20/proc=20files?=
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+* src/split.c (create): Don’t trust st_size == 0.
+---
+ src/split.c | 6 ++----
+ 1 file changed, 2 insertions(+), 4 deletions(-)
+
+diff --git a/src/split.c b/src/split.c
+index a32b2d9..862f94b 100644
+--- a/src/split.c
++++ b/src/split.c
+@@ -489,10 +489,8 @@ create (char const *name)
+       if (SAME_INODE (in_stat_buf, out_stat_buf))
+         error (EXIT_FAILURE, 0, _("%s would overwrite input; aborting"),
+                quoteaf (name));
+-      bool regularish
+-        = S_ISREG (out_stat_buf.st_mode) || S_TYPEISSHM (&out_stat_buf);
+-      if (! (regularish && out_stat_buf.st_size == 0)
+-          && ftruncate (fd, 0) < 0 && regularish)
++      if (ftruncate (fd, 0) < 0
++          && (S_ISREG (out_stat_buf.st_mode) || S_TYPEISSHM (&out_stat_buf)))
+         error (EXIT_FAILURE, errno, _("%s: error truncating"), quotef (name));
+ 
+       return fd;
+-- 
+2.27.0
+

coreutils.spec

@@ -1,6 +1,6 @@
 Name:       coreutils
 Version:    9.4
-Release:    5
+Release:    6
 License:    GPLv3+
 Summary:    A set of basic GNU tools commonly used in shell scripts
 Url:        https://www.gnu.org/software/coreutils/
@@ -25,6 +25,10 @@ patch10:   backport-CVE-2024-0684-split-do-not-shrink-hold-buffer.patch
 patch11:   test-skip-overlay-filesystem-because-of-no-inotify_add_watch.patch
 patch12:   fix-coredump-if-enable-systemd.patch
 patch13:   backport-sort-don-t-trust-st_size-on-proc-files.patch
+patch14:   backport-cat-don-t-trust-st_size-on-proc-files.patch
+patch15:   backport-dd-don-t-trust-st_size-on-proc-files.patch
+patch16:   backport-split-don-t-trust-st_size-on-proc-files.patch
+
 %ifarch sw_64
 Patch9001:   coreutils-9.0-sw.patch
 %endif
@@ -159,6 +163,9 @@ fi
 %{_mandir}/man*/*
 
 %changelog
+* Mon Jun 24 2024 huyubiao <huyubiao@huawei.com> - 9.4-6
+- backport patches from community
+
 * Wed Jun 12 2024 yanglongkang <yanglongkang@h-partners.com> - 9.4-5
 - sort: don't trust st_size on /proc files