https://github.com/torvalds/linux
Revision 86d32f9a7c54ad74f4514d7fef7c847883207291 authored by Vasily Averin on 14 April 2020, 20:33:16 UTC, committed by Linus Torvalds on 16 April 2020, 17:10:50 UTC
If seq_file .next function does not change position index, read after some lseek can generate unexpected output: $ dd if=/proc/keys bs=1 # full usual output 0f6bfdf5 I--Q--- 2 perm 3f010000 1000 1000 user 4af2f79ab8848d0a: 740 1fb91b32 I--Q--- 3 perm 1f3f0000 1000 65534 keyring _uid.1000: 2 27589480 I--Q--- 1 perm 0b0b0000 0 0 user invocation_id: 16 2f33ab67 I--Q--- 152 perm 3f030000 0 0 keyring _ses: 2 33f1d8fa I--Q--- 4 perm 3f030000 1000 1000 keyring _ses: 1 3d427fda I--Q--- 2 perm 3f010000 1000 1000 user 69ec44aec7678e5a: 740 3ead4096 I--Q--- 1 perm 1f3f0000 1000 65534 keyring _uid_ses.1000: 1 521+0 records in 521+0 records out 521 bytes copied, 0,00123769 s, 421 kB/s But a read after lseek in middle of last line results in the partial last line and then a repeat of the final line: $ dd if=/proc/keys bs=500 skip=1 dd: /proc/keys: cannot skip to specified offset g _uid_ses.1000: 1 3ead4096 I--Q--- 1 perm 1f3f0000 1000 65534 keyring _uid_ses.1000: 1 0+1 records in 0+1 records out 97 bytes copied, 0,000135035 s, 718 kB/s and a read after lseek beyond end of file results in the last line being shown: $ dd if=/proc/keys bs=1000 skip=1 # read after lseek beyond end of file dd: /proc/keys: cannot skip to specified offset 3ead4096 I--Q--- 1 perm 1f3f0000 1000 65534 keyring _uid_ses.1000: 1 0+1 records in 0+1 records out 76 bytes copied, 0,000119981 s, 633 kB/s See https://bugzilla.kernel.org/show_bug.cgi?id=206283 Fixes: 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code ...") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 0008633
Tip revision: 86d32f9a7c54ad74f4514d7fef7c847883207291 authored by Vasily Averin on 14 April 2020, 20:33:16 UTC
keys: Fix proc_keys_next to increase position index
keys: Fix proc_keys_next to increase position index
Tip revision: 86d32f9
globtest.c
/*
* Extracted fronm glob.c
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/glob.h>
#include <linux/printk.h>
/* Boot with "glob.verbose=1" to show successful tests, too */
static bool verbose = false;
module_param(verbose, bool, 0);
struct glob_test {
char const *pat, *str;
bool expected;
};
static bool __pure __init test(char const *pat, char const *str, bool expected)
{
bool match = glob_match(pat, str);
bool success = match == expected;
/* Can't get string literals into a particular section, so... */
static char const msg_error[] __initconst =
KERN_ERR "glob: \"%s\" vs. \"%s\": %s *** ERROR ***\n";
static char const msg_ok[] __initconst =
KERN_DEBUG "glob: \"%s\" vs. \"%s\": %s OK\n";
static char const mismatch[] __initconst = "mismatch";
char const *message;
if (!success)
message = msg_error;
else if (verbose)
message = msg_ok;
else
return success;
printk(message, pat, str, mismatch + 3*match);
return success;
}
/*
* The tests are all jammed together in one array to make it simpler
* to place that array in the .init.rodata section. The obvious
* "array of structures containing char *" has no way to force the
* pointed-to strings to be in a particular section.
*
* Anyway, a test consists of:
* 1. Expected glob_match result: '1' or '0'.
* 2. Pattern to match: null-terminated string
* 3. String to match against: null-terminated string
*
* The list of tests is terminated with a final '\0' instead of
* a glob_match result character.
*/
static char const glob_tests[] __initconst =
/* Some basic tests */
"1" "a\0" "a\0"
"0" "a\0" "b\0"
"0" "a\0" "aa\0"
"0" "a\0" "\0"
"1" "\0" "\0"
"0" "\0" "a\0"
/* Simple character class tests */
"1" "[a]\0" "a\0"
"0" "[a]\0" "b\0"
"0" "[!a]\0" "a\0"
"1" "[!a]\0" "b\0"
"1" "[ab]\0" "a\0"
"1" "[ab]\0" "b\0"
"0" "[ab]\0" "c\0"
"1" "[!ab]\0" "c\0"
"1" "[a-c]\0" "b\0"
"0" "[a-c]\0" "d\0"
/* Corner cases in character class parsing */
"1" "[a-c-e-g]\0" "-\0"
"0" "[a-c-e-g]\0" "d\0"
"1" "[a-c-e-g]\0" "f\0"
"1" "[]a-ceg-ik[]\0" "a\0"
"1" "[]a-ceg-ik[]\0" "]\0"
"1" "[]a-ceg-ik[]\0" "[\0"
"1" "[]a-ceg-ik[]\0" "h\0"
"0" "[]a-ceg-ik[]\0" "f\0"
"0" "[!]a-ceg-ik[]\0" "h\0"
"0" "[!]a-ceg-ik[]\0" "]\0"
"1" "[!]a-ceg-ik[]\0" "f\0"
/* Simple wild cards */
"1" "?\0" "a\0"
"0" "?\0" "aa\0"
"0" "??\0" "a\0"
"1" "?x?\0" "axb\0"
"0" "?x?\0" "abx\0"
"0" "?x?\0" "xab\0"
/* Asterisk wild cards (backtracking) */
"0" "*??\0" "a\0"
"1" "*??\0" "ab\0"
"1" "*??\0" "abc\0"
"1" "*??\0" "abcd\0"
"0" "??*\0" "a\0"
"1" "??*\0" "ab\0"
"1" "??*\0" "abc\0"
"1" "??*\0" "abcd\0"
"0" "?*?\0" "a\0"
"1" "?*?\0" "ab\0"
"1" "?*?\0" "abc\0"
"1" "?*?\0" "abcd\0"
"1" "*b\0" "b\0"
"1" "*b\0" "ab\0"
"0" "*b\0" "ba\0"
"1" "*b\0" "bb\0"
"1" "*b\0" "abb\0"
"1" "*b\0" "bab\0"
"1" "*bc\0" "abbc\0"
"1" "*bc\0" "bc\0"
"1" "*bc\0" "bbc\0"
"1" "*bc\0" "bcbc\0"
/* Multiple asterisks (complex backtracking) */
"1" "*ac*\0" "abacadaeafag\0"
"1" "*ac*ae*ag*\0" "abacadaeafag\0"
"1" "*a*b*[bc]*[ef]*g*\0" "abacadaeafag\0"
"0" "*a*b*[ef]*[cd]*g*\0" "abacadaeafag\0"
"1" "*abcd*\0" "abcabcabcabcdefg\0"
"1" "*ab*cd*\0" "abcabcabcabcdefg\0"
"1" "*abcd*abcdef*\0" "abcabcdabcdeabcdefg\0"
"0" "*abcd*\0" "abcabcabcabcefg\0"
"0" "*ab*cd*\0" "abcabcabcabcefg\0";
static int __init glob_init(void)
{
unsigned successes = 0;
unsigned n = 0;
char const *p = glob_tests;
static char const message[] __initconst =
KERN_INFO "glob: %u self-tests passed, %u failed\n";
/*
* Tests are jammed together in a string. The first byte is '1'
* or '0' to indicate the expected outcome, or '\0' to indicate the
* end of the tests. Then come two null-terminated strings: the
* pattern and the string to match it against.
*/
while (*p) {
bool expected = *p++ & 1;
char const *pat = p;
p += strlen(p) + 1;
successes += test(pat, p, expected);
p += strlen(p) + 1;
n++;
}
n -= successes;
printk(message, successes, n);
/* What's the errno for "kernel bug detected"? Guess... */
return n ? -ECANCELED : 0;
}
/* We need a dummy exit function to allow unload */
static void __exit glob_fini(void) { }
module_init(glob_init);
module_exit(glob_fini);
MODULE_DESCRIPTION("glob(7) matching tests");
MODULE_LICENSE("Dual MIT/GPL");
Computing file changes ...