xiaomi-sm8450/android_kernel_xiaomi_sm8450
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Fix races around the access to ->s_options

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Put generic_show_options read access to s_options under rcu_read_lock,
split save_mount_options() into "we are setting it the first time"
(uses in foo_fill_super()) and "we are relacing and freeing the old one",
synchronize_rcu() before kfree() in the latter.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
2009-05-08 16:05:57 -04:00
parent f9dbd05bc9
commit 2a32cebd6c
7 changed files with 25 additions and 13 deletions
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4
fs/afs/super.c
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@@ -408,17 +408,17 @@ static int afs_get_sb(struct file_system_type *fs_type,
deactivate_locked_super(sb);
goto error;
}
sb->s_options = new_opts;
save_mount_options(sb, new_opts);
sb->s_flags |= MS_ACTIVE;
} else {
_debug("reuse");
kfree(new_opts);
ASSERTCMP(sb->s_flags, &, MS_ACTIVE);
}
simple_set_mnt(mnt, sb);
afs_put_volume(params.volume);
afs_put_cell(params.cell);
kfree(new_opts);
_leave(" = 0 [%p]", sb);
return 0;