diff options
| author | Florian Westphal <fw@strlen.de> | 2025-06-24 23:20:58 +0200 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2025-08-13 20:47:40 +0200 |
| commit | 8c5680ae9ab9aa4880118dab85d9201f71a23aa3 (patch) | |
| tree | 10ac7b292fe9143d7fc42a86738fc57104d59553 | |
| parent | 535689d466f46ead3ff4377da58668e6e614983e (diff) | |
evaluate: avoid double-free on error handling of bogus objref maps
commit ab1139f807f0d0519a25704e75c442ccb71f7a60 upstream.
commit 98c51aaac42b ("evaluate: bail out if anonymous concat set defines a non concat expression")
clears set->init to avoid a double-free.
Extend this to also handle object maps.
The included bogon triggers a double-free of set->init expression:
Error: unqualified type invalid specified in map definition. Try "typeof expression" instead of "type datatype".
ct helper set ct saddr map { 1c3:: : "p", dead::beef : "myftp" }
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
This might not crash, depending on libc/malloc, but ASAN reports this:
==17728==ERROR: AddressSanitizer: heap-use-after-free on address 0x50b0000005e8 at ..
READ of size 4 at 0x50b0000005e8 thread T0
#0 0x7f1be3cb7526 in expr_free src/expression.c:87
#1 0x7f1be3cbdf29 in map_expr_destroy src/expression.c:1488
#2 0x7f1be3cb74d5 in expr_destroy src/expression.c:80
#3 0x7f1be3cb75c6 in expr_free src/expression.c:96
#4 0x7f1be3d5925e in objref_stmt_destroy src/statement.c:331
#5 0x7f1be3d5831f in stmt_free src/statement.c:56
#6 0x7f1be3d583c2 in stmt_list_free src/statement.c:66
#7 0x7f1be3d42805 in rule_free src/rule.c:495
#8 0x7f1be3d48329 in cmd_free src/rule.c:1417
#9 0x7f1be3cd2c7c in __nft_run_cmd_from_filename src/libnftables.c:759
#10 0x7f1be3cd340c in nft_run_cmd_from_filename src/libnftables.c:847
#11 0x55dcde0440be in main src/main.c:535
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Pablo Neira Ayuso <pablo@netfilter.org>
| -rw-r--r-- | src/evaluate.c | 2 | ||||
| -rw-r--r-- | tests/shell/testcases/bogons/objref_double_free_crash | 10 |
2 files changed, 11 insertions, 1 deletions
diff --git a/src/evaluate.c b/src/evaluate.c index 72baf585..459b5095 100644 --- a/src/evaluate.c +++ b/src/evaluate.c @@ -128,7 +128,7 @@ static struct expr *implicit_set_declaration(struct eval_ctx *ctx, set->automerge = set->flags & NFT_SET_INTERVAL; if (set_evaluate(ctx, set) < 0) { - if (set->flags & NFT_SET_MAP) + if (set->flags & (NFT_SET_MAP|NFT_SET_OBJECT)) set->init = NULL; set_free(set); return NULL; diff --git a/tests/shell/testcases/bogons/objref_double_free_crash b/tests/shell/testcases/bogons/objref_double_free_crash new file mode 100644 index 00000000..52b0435b --- /dev/null +++ b/tests/shell/testcases/bogons/objref_double_free_crash @@ -0,0 +1,10 @@ +table arp test { + ct helper myftp { + type "ftp" protocol tcp + l3proto inet + } + + chain y { + ct helper set ct saddr map { 1c3:: : "p", dead::beef : "myftp" } + } +} |