From b4cf6cac73725d988957410116ddf088546239ca Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Mon, 6 Nov 2023 17:25:38 -0300 Subject: [PATCH] elf: Do not process invalid tunable format 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. Reviewed-by: Siddhesh Poyarekar --- 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 f7dca8f7c1..082a76d9c4 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 d874b73b68..7fe9907e05 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, } }; -- 2.11.4.GIT