user/sven/linux.git/include/linux/seq_file.h, branch v3.2.78

fs: create and use seq_show_option for escaping

2015-10-13T02:46:08Z

commit a068acf2ee77693e0bf39d6e07139ba704f461c3 upstream. Many file systems that implement the show_options hook fail to correctly escape their output which could lead to unescaped characters (e.g. new lines) leaking into /proc/mounts and /proc/[pid]/mountinfo files. This could lead to confusion, spoofed entries (resulting in things like systemd issuing false d-bus "mount" notifications), and who knows what else. This looks like it would only be the root user stepping on themselves, but it's possible weird things could happen in containers or in other situations with delegated mount privileges. Here's an example using overlay with setuid fusermount trusting the contents of /proc/mounts (via the /etc/mtab symlink). Imagine the use of "sudo" is something more sneaky: $ BASE="ovl" $ MNT="$BASE/mnt" $ LOW="$BASE/lower" $ UP="$BASE/upper" $ WORK="$BASE/work/ 0 0 none /proc fuse.pwn user_id=1000" $ mkdir -p "$LOW" "$UP" "$WORK" $ sudo mount -t overlay -o "lowerdir=$LOW,upperdir=$UP,workdir=$WORK" none /mnt $ cat /proc/mounts none /root/ovl/mnt overlay rw,relatime,lowerdir=ovl/lower,upperdir=ovl/upper,workdir=ovl/work/ 0 0 none /proc fuse.pwn user_id=1000 0 0 $ fusermount -u /proc $ cat /proc/mounts cat: /proc/mounts: No such file or directory This fixes the problem by adding new seq_show_option and seq_show_option_n helpers, and updating the vulnerable show_option handlers to use them as needed. Some, like SELinux, need to be open coded due to unusual existing escape mechanisms. [akpm@linux-foundation.org: add lost chunk, per Kees] [keescook@chromium.org: seq_show_option should be using const parameters] Signed-off-by: Kees Cook Acked-by: Serge Hallyn Acked-by: Jan Kara Acked-by: Paul Moore Cc: J. R. Okajima Signed-off-by: Kees Cook Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds [bwh: Backported to 3.2: - Drop changes to overlayfs, reiserfs - Drop vers option from cifs - ceph changes are all in one file - Adjust context] Signed-off-by: Ben Hutchings

treewide: use printf not attribute__((format(printf,...)))

2011-11-01T00:30:54Z

Standardize the style for compiler based printf format verification. Standardized the location of __printf too. Done via script and a little typing. $ grep -rPl --include=*.[ch] -w "__attribute__" * | \ grep -vP "^(tools|scripts|include/linux/compiler-gcc.h)" | \ xargs perl -n -i -e 'local $/; while (<>) { s/\b__attribute__\s*$\s*\(\s*format\s*\(\s*printf\s*,\s*(.+)\s*,\s*(.+)\s*$\s*\)\s*\)/__printf($1, $2)/g ; print; }' [akpm@linux-foundation.org: revert arch bits] Signed-off-by: Joe Perches Cc: "Kirill A. Shutemov" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fs: seq_file - add event counter to simplify poll() support

2011-07-21T00:47:50Z

Moving the event counter into the dynamically allocated 'struc seq_file' allows poll() support without the need to allocate its own tracking structure. All current users are switched over to use the new counter. Requested-by: Andrew Morton akpm@linux-foundation.org Acked-by: NeilBrown Tested-by: Lucas De Marchi lucas.demarchi@profusion.mobi Signed-off-by: Kay Sievers Signed-off-by: Al Viro

seq_file: add RCU versions of new hlist/list iterators (v3)

2010-02-22T23:45:54Z

Many usages of seq_file use RCU protected lists, so non RCU iterators will not work safely. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller

seq_file: Add helpers for iteration over a hlist

2010-02-10T19:12:06Z

Some places in kernel need to iterate over a hlist in seq_file, so provide some common helpers. Signed-off-by: Li Zefan Signed-off-by: David S. Miller

vfs: seq_file: add helpers for data filling

2009-09-24T11:47:35Z

Add two helpers that allow access to the seq_file's own buffer, but hide the internal details of seq_files. This allows easier implementation of special purpose filling functions. It also cleans up some existing functions which duplicated the seq_file logic. Make these inline functions in seq_file.h, as suggested by Al. Signed-off-by: Miklos Szeredi Acked-by: Hugh Dickins Signed-off-by: Al Viro

seq_file: add function to write binary data

2009-06-18T20:03:57Z

seq_write() can be used to construct seq_files containing arbitrary data. Required by the gcov-profiling interface to synthesize binary profiling data files. Signed-off-by: Peter Oberparleiter Cc: Andi Kleen Cc: Huang Ying Cc: Li Wei Cc: Michael Ellerman Cc: Ingo Molnar Cc: Heiko Carstens Cc: Martin Schwidefsky Cc: Rusty Russell Cc: WANG Cong Cc: Sam Ravnborg Cc: Jeff Dike Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

cpumask: fix seq_bitmap_*() functions.

2009-03-30T11:35:11Z

1) seq_bitmap_list() should take a const. 2) All the seq_bitmap should use cpumask_bits(). Signed-off-by: Rusty Russell

seq_file: properly cope with pread

2009-02-18T23:37:53Z

Currently seq_read assumes that the offset passed to it is always the offset it passed to user space. In the case pread this assumption is broken and we do the wrong thing when presented with pread. To solve this I introduce an offset cache inside of struct seq_file so we know where our logical file position is. Then in seq_read if we try to read from another offset we reset our data structures and attempt to go to the offset user space wanted. [akpm@linux-foundation.org: restore FMODE_PWRITE] [pjt@google.com: seq_open needs its fmode opened up to take advantage of this] Signed-off-by: Eric Biederman Cc: Alexey Dobriyan Cc: Al Viro Cc: Paul Turner Cc: [2.6.25.x, 2.6.26.x, 2.6.27.x, 2.6.28.x] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

cpumask: Use nr_cpu_ids in seq_cpumask

2008-12-29T22:35:19Z

Impact: cleanup, futureproof nr_cpu_ids is the (badly named) runtime limit on possible CPU numbers; ie. the variable version of NR_CPUS. With the new cpumask operators, only bits less than this are defined. So we should use it everywhere, rather than NR_CPUS. Eventually this will make it possible to allocate cpumasks of the minimal length at runtime. Signed-off-by: Rusty Russell Signed-off-by: Mike Travis Acked-by: Ingo Molnar