diff options
| author | Herbert Xu <herbert@gondor.apana.org.au> | 2021-06-21 17:57:19 +0800 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2021-09-03 15:02:45 +0800 |
| commit | 2cb4711364517add3ef204863e1993241ba18c54 (patch) | |
| tree | 857aca678bce2a3fa8cb2d415ad71e3b3748b61e | |
| parent | Release 0.5.11.4. (diff) | |
| download | dash-2cb4711364517add3ef204863e1993241ba18c54.tar.gz dash-2cb4711364517add3ef204863e1993241ba18c54.zip | |
parser: Fix VSLENGTH parsing with trailing garbage
On Sat, Jun 19, 2021 at 02:44:46PM +0200, Denys Vlasenko wrote:
>
> CTLVAR and CTLBACKQ are not properly handled if encountered
> inside {$#...}. Testcase:
>
> dash -c "`printf 'echo ${#1\x82}'`" 00 111 222
>
> It should execute "echo ${#1 <byte 0x82> }" and thus print "3"
> (the length of $1, which is "111").
>
> Instead, it segfaults.
>
> (Ideally, it should fail since "1 <byte 0x82>" is not a valid
> variable name, but currently dash accepts e.g. "${#1abc}"
> as if it is "${#1}bc". A separate, less serious bug...).
In fact these two bugs are one and the same. This patch fixes
both by detecting the invalid substitution and not emitting it
into the node tree.
Incidentally this reveals a bug in how we parse ${#10} that got
introduced recently, which is also fixed here.
Reported-by: Denys Vlasenko <vda.linux@googlemail.com>
Fixes: 7710a926b321 ("parser: Only accept single-digit parameter...")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
| -rw-r--r-- | src/parser.c | 5 | ||||
| -rw-r--r-- | src/parser.h | 1 |
2 files changed, 5 insertions, 1 deletions
diff --git a/src/parser.c b/src/parser.c index a47022e..fc9af07 100644 --- a/src/parser.c +++ b/src/parser.c @@ -1262,7 +1262,8 @@ varname: do { STPUTC(c, out); c = pgetc_eatbnl(); - } while (!subtype && is_digit(c)); + } while ((subtype <= 0 || subtype >= VSLENGTH) && + is_digit(c)); } else if (c != '}') { int cc = c; @@ -1322,6 +1323,8 @@ varname: break; } } else { + if (subtype == VSLENGTH && c != '}') + subtype = 0; badsub: pungetc(); } diff --git a/src/parser.h b/src/parser.h index 524ac1c..7d2749b 100644 --- a/src/parser.h +++ b/src/parser.h @@ -62,6 +62,7 @@ #define VSTRIMLEFT 0x8 /* ${var#pattern} */ #define VSTRIMLEFTMAX 0x9 /* ${var##pattern} */ #define VSLENGTH 0xa /* ${#var} */ +/* VSLENGTH must come last. */ /* values of checkkwd variable */ #define CHKALIAS 0x1 |