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| author | Eric Sandeen <sandeen@redhat.com> | 2011-11-11 21:06:04 -0500 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2011-11-11 21:06:04 -0500 |
| commit | df7a86d404e293465b8e5f39859c0916e84ba35a (patch) | |
| tree | dc5f9bf3ef2c70969e1b91cff8fca7bbaca65436 | |
| parent | 7105c183a0f4622268a50db37017cfacc9877e5f (diff) | |
| download | android_external_e2fsprogs-df7a86d404e293465b8e5f39859c0916e84ba35a.tar.gz android_external_e2fsprogs-df7a86d404e293465b8e5f39859c0916e84ba35a.tar.bz2 android_external_e2fsprogs-df7a86d404e293465b8e5f39859c0916e84ba35a.zip | |
libext2fs: fix write size in ext2fs_mmp_write
Without this change, we will write data past the end of the
mmp buf. Valgrind catches this:
==6373== Syscall param write(buf) points to unaddressable byte(s)
==6373== at 0x362260E470: __write_nocancel (in /lib64/libpthread-2.12.2.so)
==6373== by 0x41CF83: raw_write_blk (unix_io.c:255)
==6373== by 0x41D2BC: unix_write_blk64 (unix_io.c:757)
==6373== by 0x41A05D: ext2fs_mmp_write (mmp.c:130)
==6373== by 0x40B0C9: do_set_mmp_value (set_fields.c:806)
==6373== by 0x421B61: really_execute_command (execute_cmd.c:108)
==6373== by 0x421C54: ss_execute_line (execute_cmd.c:234)
==6373== by 0x403743: main (debugfs.c:2339)
==6373== Address 0x63f000 is not stack'd, malloc'd or (recently) free'd
and in my testing it led to silent failures while writing the mmp
block in debugfs:
write(3, "xV4\22PMM\342\325V\274N\0\0\0\0host.name."..., 4096) = -1 EFAULT (Bad address)
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| -rw-r--r-- | lib/ext2fs/mmp.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/ext2fs/mmp.c b/lib/ext2fs/mmp.c index 91f4fb28..b27d9a42 100644 --- a/lib/ext2fs/mmp.c +++ b/lib/ext2fs/mmp.c @@ -127,7 +127,7 @@ errcode_t ext2fs_mmp_write(ext2_filsys fs, blk64_t mmp_blk, void *buf) /* I was tempted to make this use O_DIRECT and the mmp_fd, but * this caused no end of grief, while leaving it as-is works. */ - retval = io_channel_write_blk64(fs->io, mmp_blk, -fs->blocksize, buf); + retval = io_channel_write_blk64(fs->io, mmp_blk, -(int)sizeof(struct mmp_struct), buf); #ifdef WORDS_BIGENDIAN ext2fs_swap_mmp(mmp_s); |