From b64d09a4e8596f76d27f4b4a90a1cf6baf6a82f8 Mon Sep 17 00:00:00 2001 From: "Christian A. Ehrhardt" Date: Fri, 29 Dec 2023 11:54:11 +0100 Subject: [PATCH] of: Fix double free in of_parse_phandle_with_args_map [ Upstream commit 4dde83569832f9377362e50f7748463340c5db6b ] In of_parse_phandle_with_args_map() the inner loop that iterates through the map entries calls of_node_put(new) to free the reference acquired by the previous iteration of the inner loop. This assumes that the value of "new" is NULL on the first iteration of the inner loop. Make sure that this is true in all iterations of the outer loop by setting "new" to NULL after its value is assigned to "cur". Extend the unittest to detect the double free and add an additional test case that actually triggers this path. Fixes: bd6f2fd5a1 ("of: Support parsing phandle argument lists through a nexus node") Cc: Stephen Boyd Signed-off-by: "Christian A. Ehrhardt" Link: https://lore.kernel.org/r/20231229105411.1603434-1-lk@c--e.de Signed-off-by: Rob Herring Signed-off-by: Sasha Levin --- drivers/of/base.c | 1 + drivers/of/unittest-data/tests-phandle.dtsi | 10 +++- drivers/of/unittest.c | 74 +++++++++++++++++------------ 3 files changed, 53 insertions(+), 32 deletions(-) diff --git a/drivers/of/base.c b/drivers/of/base.c index 8d93cb6..b0ad8fc 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -1464,6 +1464,7 @@ int of_parse_phandle_with_args_map(const struct device_node *np, out_args->np = new; of_node_put(cur); cur = new; + new = NULL; } put: of_node_put(cur); diff --git a/drivers/of/unittest-data/tests-phandle.dtsi b/drivers/of/unittest-data/tests-phandle.dtsi index d01f92f..554a996 100644 --- a/drivers/of/unittest-data/tests-phandle.dtsi +++ b/drivers/of/unittest-data/tests-phandle.dtsi @@ -40,6 +40,13 @@ phandle-map-pass-thru = <0x0 0xf0>; }; + provider5: provider5 { + #phandle-cells = <2>; + phandle-map = <2 7 &provider4 2 3>; + phandle-map-mask = <0xff 0xf>; + phandle-map-pass-thru = <0x0 0xf0>; + }; + consumer-a { phandle-list = <&provider1 1>, <&provider2 2 0>, @@ -66,7 +73,8 @@ <&provider4 4 0x100>, <&provider4 0 0x61>, <&provider0>, - <&provider4 19 0x20>; + <&provider4 19 0x20>, + <&provider5 2 7>; phandle-list-bad-phandle = <12345678 0 0>; phandle-list-bad-args = <&provider2 1 0>, <&provider4 0>; diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c index ad2b787..c63f596 100644 --- a/drivers/of/unittest.c +++ b/drivers/of/unittest.c @@ -456,6 +456,9 @@ static void __init of_unittest_parse_phandle_with_args(void) unittest(passed, "index %i - data error on node %pOF rc=%i\n", i, args.np, rc); + + if (rc == 0) + of_node_put(args.np); } /* Check for missing list property */ @@ -545,8 +548,9 @@ static void __init of_unittest_parse_phandle_with_args(void) static void __init of_unittest_parse_phandle_with_args_map(void) { - struct device_node *np, *p0, *p1, *p2, *p3; + struct device_node *np, *p[6] = {}; struct of_phandle_args args; + unsigned int prefs[6]; int i, rc; np = of_find_node_by_path("/testcase-data/phandle-tests/consumer-b"); @@ -555,34 +559,24 @@ static void __init of_unittest_parse_phandle_with_args_map(void) return; } - p0 = of_find_node_by_path("/testcase-data/phandle-tests/provider0"); - if (!p0) { - pr_err("missing testcase data\n"); - return; - } - - p1 = of_find_node_by_path("/testcase-data/phandle-tests/provider1"); - if (!p1) { - pr_err("missing testcase data\n"); - return; - } - - p2 = of_find_node_by_path("/testcase-data/phandle-tests/provider2"); - if (!p2) { - pr_err("missing testcase data\n"); - return; - } - - p3 = of_find_node_by_path("/testcase-data/phandle-tests/provider3"); - if (!p3) { - pr_err("missing testcase data\n"); - return; + p[0] = of_find_node_by_path("/testcase-data/phandle-tests/provider0"); + p[1] = of_find_node_by_path("/testcase-data/phandle-tests/provider1"); + p[2] = of_find_node_by_path("/testcase-data/phandle-tests/provider2"); + p[3] = of_find_node_by_path("/testcase-data/phandle-tests/provider3"); + p[4] = of_find_node_by_path("/testcase-data/phandle-tests/provider4"); + p[5] = of_find_node_by_path("/testcase-data/phandle-tests/provider5"); + for (i = 0; i < ARRAY_SIZE(p); ++i) { + if (!p[i]) { + pr_err("missing testcase data\n"); + return; + } + prefs[i] = kref_read(&p[i]->kobj.kref); } rc = of_count_phandle_with_args(np, "phandle-list", "#phandle-cells"); - unittest(rc == 7, "of_count_phandle_with_args() returned %i, expected 7\n", rc); + unittest(rc == 8, "of_count_phandle_with_args() returned %i, expected 7\n", rc); - for (i = 0; i < 8; i++) { + for (i = 0; i < 9; i++) { bool passed = true; memset(&args, 0, sizeof(args)); @@ -593,13 +587,13 @@ static void __init of_unittest_parse_phandle_with_args_map(void) switch (i) { case 0: passed &= !rc; - passed &= (args.np == p1); + passed &= (args.np == p[1]); passed &= (args.args_count == 1); passed &= (args.args[0] == 1); break; case 1: passed &= !rc; - passed &= (args.np == p3); + passed &= (args.np == p[3]); passed &= (args.args_count == 3); passed &= (args.args[0] == 2); passed &= (args.args[1] == 5); @@ -610,28 +604,36 @@ static void __init of_unittest_parse_phandle_with_args_map(void) break; case 3: passed &= !rc; - passed &= (args.np == p0); + passed &= (args.np == p[0]); passed &= (args.args_count == 0); break; case 4: passed &= !rc; - passed &= (args.np == p1); + passed &= (args.np == p[1]); passed &= (args.args_count == 1); passed &= (args.args[0] == 3); break; case 5: passed &= !rc; - passed &= (args.np == p0); + passed &= (args.np == p[0]); passed &= (args.args_count == 0); break; case 6: passed &= !rc; - passed &= (args.np == p2); + passed &= (args.np == p[2]); passed &= (args.args_count == 2); passed &= (args.args[0] == 15); passed &= (args.args[1] == 0x20); break; case 7: + passed &= !rc; + passed &= (args.np == p[3]); + passed &= (args.args_count == 3); + passed &= (args.args[0] == 2); + passed &= (args.args[1] == 5); + passed &= (args.args[2] == 3); + break; + case 8: passed &= (rc == -ENOENT); break; default: @@ -640,6 +642,9 @@ static void __init of_unittest_parse_phandle_with_args_map(void) unittest(passed, "index %i - data error on node %s rc=%i\n", i, args.np->full_name, rc); + + if (rc == 0) + of_node_put(args.np); } /* Check for missing list property */ @@ -686,6 +691,13 @@ static void __init of_unittest_parse_phandle_with_args_map(void) "OF: /testcase-data/phandle-tests/consumer-b: #phandle-cells = 2 found 1"); unittest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc); + + for (i = 0; i < ARRAY_SIZE(p); ++i) { + unittest(prefs[i] == kref_read(&p[i]->kobj.kref), + "provider%d: expected:%d got:%d\n", + i, prefs[i], kref_read(&p[i]->kobj.kref)); + of_node_put(p[i]); + } } static void __init of_unittest_property_string(void) -- 2.7.4