| Message ID | 20231017130526.2216827-6-adhemerval.zanella@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Improve loader environment variable handling | expand |
On 2023-10-17 09:05, Adhemerval Zanella wrote: > Tunable definitions with more than one '=' on are parsed and enabled, > and any subsequent '=' are ignored. It means that tunables in the form > 'tunable=tunable=value' or 'tunable=value=value' are handled as > 'tunable=value'. These inputs are likely user input errors, which > should not be accepted. > > Checked on x86_64-linux-gnu. > --- > elf/dl-tunables.c | 6 ++++-- > elf/tst-tunables.c | 22 +++++++++++++++++----- > 2 files changed, 21 insertions(+), 7 deletions(-) > > diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c > index a83bd2b8bc..59bee61124 100644 > --- a/elf/dl-tunables.c > +++ b/elf/dl-tunables.c > @@ -192,10 +192,12 @@ parse_tunables (char *valstring) > > const char *value = p; > > - while (*p != ':' && *p != '\0') > + while (*p != '=' && *p != ':' && *p != '\0') > p++; > > - if (*p == '\0') > + if (*p == '=') > + break; > + else if (*p == '\0') So we're not going to attempt to parse any tunables after the malformed one. A bit harsh, but probably safer. OK. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org> > done = true; > else > *p++ = '\0'; > diff --git a/elf/tst-tunables.c b/elf/tst-tunables.c > index 57cf532fc4..03039b5260 100644 > --- a/elf/tst-tunables.c > +++ b/elf/tst-tunables.c > @@ -161,24 +161,36 @@ static const struct test_t > 0, > 0, > }, > - /* The ill-formatted tunable is also skipped. */ > + /* If there is a ill-formatted key=value, everything after is also ignored. */ > { > "glibc.malloc.mmap_threshold=glibc.malloc.mmap_threshold=4096:glibc.malloc.check=2", > - 2, > + 0, > 0, > 0, > }, > - /* For an integer tunable, parse will stop on non number character. */ > { > "glibc.malloc.check=2=2", > - 2, > + 0, > 0, > 0, > }, > { > "glibc.malloc.check=2=2:glibc.malloc.mmap_threshold=4096", > + 0, > + 0, > + 0, > + }, > + { > + "glibc.malloc.check=2=2:glibc.malloc.check=2", > + 0, > + 0, > + 0, > + }, > + /* Valid tunables set before ill-formatted ones are set. */ > + { > + "glibc.malloc.check=2:glibc.malloc.mmap_threshold=4096=4096", > 2, > - 4096, > + 0, > 0, > } > };
diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c index a83bd2b8bc..59bee61124 100644 --- a/elf/dl-tunables.c +++ b/elf/dl-tunables.c @@ -192,10 +192,12 @@ parse_tunables (char *valstring) const char *value = p; - while (*p != ':' && *p != '\0') + while (*p != '=' && *p != ':' && *p != '\0') p++; - if (*p == '\0') + if (*p == '=') + break; + else if (*p == '\0') done = true; else *p++ = '\0'; diff --git a/elf/tst-tunables.c b/elf/tst-tunables.c index 57cf532fc4..03039b5260 100644 --- a/elf/tst-tunables.c +++ b/elf/tst-tunables.c @@ -161,24 +161,36 @@ static const struct test_t 0, 0, }, - /* The ill-formatted tunable is also skipped. */ + /* If there is a ill-formatted key=value, everything after is also ignored. */ { "glibc.malloc.mmap_threshold=glibc.malloc.mmap_threshold=4096:glibc.malloc.check=2", - 2, + 0, 0, 0, }, - /* For an integer tunable, parse will stop on non number character. */ { "glibc.malloc.check=2=2", - 2, + 0, 0, 0, }, { "glibc.malloc.check=2=2:glibc.malloc.mmap_threshold=4096", + 0, + 0, + 0, + }, + { + "glibc.malloc.check=2=2:glibc.malloc.check=2", + 0, + 0, + 0, + }, + /* Valid tunables set before ill-formatted ones are set. */ + { + "glibc.malloc.check=2:glibc.malloc.mmap_threshold=4096=4096", 2, - 4096, + 0, 0, } };