| Message ID | 20200623003236.830149-4-tyhicks@linux.microsoft.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ima: Fix rule parsing bugs and extend KEXEC_CMDLINE rule support | expand |
On Mon, 2020-06-22 at 19:32 -0500, Tyler Hicks wrote: > Use ima_free_rule() to fix memory leaks of allocated ima_rule_entry > members, such as .fsname and .keyrings, when deleting a list of rules. > > This fixes a memory leak seen when loading by a valid rule that contains > an additional piece of allocated memory, such as an fsname, followed by > an invalid rule that triggers a policy load failure: > > # echo -e "dont_measure fsname=securityfs\nbad syntax" > \ > /sys/kernel/security/ima/policy > -bash: echo: write error: Invalid argument > # echo scan > /sys/kernel/debug/kmemleak > # cat /sys/kernel/debug/kmemleak > unreferenced object 0xffff9bab67ca12c0 (size 16): > comm "tee", pid 684, jiffies 4295212803 (age 252.344s) > hex dump (first 16 bytes): > 73 65 63 75 72 69 74 79 66 73 00 6b 6b 6b 6b a5 securityfs.kkkk. > backtrace: > [<00000000adc80b1b>] kstrdup+0x2e/0x60 > [<00000000d504cb0d>] ima_parse_add_rule+0x7d4/0x1020 > [<00000000444825ac>] ima_write_policy+0xab/0x1d0 > [<000000002b7f0d6c>] vfs_write+0xde/0x1d0 > [<0000000096feedcf>] ksys_write+0x68/0xe0 > [<0000000052b544a2>] do_syscall_64+0x56/0xa0 > [<000000007ead1ba7>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > Fixes: f1b08bbcbdaf ("ima: define a new policy condition based on the filesystem name") > Fixes: 2b60c0ecedf8 ("IMA: Read keyrings= option from the IMA policy") > Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> Thanks! Thinking about it some more. It makes more sense to define ima_free_rule() here in this patch. Mimi > --- > security/integrity/ima/ima_policy.c | 6 +----- > 1 file changed, 1 insertion(+), 5 deletions(-) > > diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c > index 1320333201c6..94ca3b8abb69 100644 > --- a/security/integrity/ima/ima_policy.c > +++ b/security/integrity/ima/ima_policy.c > @@ -1431,15 +1431,11 @@ ssize_t ima_parse_add_rule(char *rule) > void ima_delete_rules(void) > { > struct ima_rule_entry *entry, *tmp; > - int i; > > temp_ima_appraise = 0; > list_for_each_entry_safe(entry, tmp, &ima_temp_rules, list) { > - for (i = 0; i < MAX_LSM_RULES; i++) > - kfree(entry->lsm[i].args_p); > - > list_del(&entry->list); > - kfree(entry); > + ima_free_rule(entry); > } > } >
On Mon, 2020-06-22 at 19:32 -0500, Tyler Hicks wrote: > Use ima_free_rule() to fix memory leaks of allocated ima_rule_entry > members, such as .fsname and .keyrings, when deleting a list of rules. > > This fixes a memory leak seen when loading by a valid rule that contains > an additional piece of allocated memory, such as an fsname, followed by > an invalid rule that triggers a policy load failure: > > # echo -e "dont_measure fsname=securityfs\nbad syntax" > \ > /sys/kernel/security/ima/policy > -bash: echo: write error: Invalid argument > # echo scan > /sys/kernel/debug/kmemleak > # cat /sys/kernel/debug/kmemleak > unreferenced object 0xffff9bab67ca12c0 (size 16): > comm "tee", pid 684, jiffies 4295212803 (age 252.344s) > hex dump (first 16 bytes): > 73 65 63 75 72 69 74 79 66 73 00 6b 6b 6b 6b a5 securityfs.kkkk. > backtrace: > [<00000000adc80b1b>] kstrdup+0x2e/0x60 > [<00000000d504cb0d>] ima_parse_add_rule+0x7d4/0x1020 > [<00000000444825ac>] ima_write_policy+0xab/0x1d0 > [<000000002b7f0d6c>] vfs_write+0xde/0x1d0 > [<0000000096feedcf>] ksys_write+0x68/0xe0 > [<0000000052b544a2>] do_syscall_64+0x56/0xa0 > [<000000007ead1ba7>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > Fixes: f1b08bbcbdaf ("ima: define a new policy condition based on the filesystem name") > Fixes: 2b60c0ecedf8 ("IMA: Read keyrings= option from the IMA policy") > Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> Your decision, but you might consider squashing this patch with 3/12. Everything all together in one patch. Mimi > --- > security/integrity/ima/ima_policy.c | 6 +----- > 1 file changed, 1 insertion(+), 5 deletions(-) > > diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c > index 1320333201c6..94ca3b8abb69 100644 > --- a/security/integrity/ima/ima_policy.c > +++ b/security/integrity/ima/ima_policy.c > @@ -1431,15 +1431,11 @@ ssize_t ima_parse_add_rule(char *rule) > void ima_delete_rules(void) > { > struct ima_rule_entry *entry, *tmp; > - int i; > > temp_ima_appraise = 0; > list_for_each_entry_safe(entry, tmp, &ima_temp_rules, list) { > - for (i = 0; i < MAX_LSM_RULES; i++) > - kfree(entry->lsm[i].args_p); > - > list_del(&entry->list); > - kfree(entry); > + ima_free_rule(entry); > } > } >
On Thu, 2020-06-25 at 17:07 -0400, Mimi Zohar wrote: > On Mon, 2020-06-22 at 19:32 -0500, Tyler Hicks wrote: > > Use ima_free_rule() to fix memory leaks of allocated ima_rule_entry > > members, such as .fsname and .keyrings, when deleting a list of rules. > > > > This fixes a memory leak seen when loading by a valid rule that contains > > an additional piece of allocated memory, such as an fsname, followed by > > an invalid rule that triggers a policy load failure: > > > > # echo -e "dont_measure fsname=securityfs\nbad syntax" > \ > > /sys/kernel/security/ima/policy > > -bash: echo: write error: Invalid argument > > # echo scan > /sys/kernel/debug/kmemleak > > # cat /sys/kernel/debug/kmemleak > > unreferenced object 0xffff9bab67ca12c0 (size 16): > > comm "tee", pid 684, jiffies 4295212803 (age 252.344s) > > hex dump (first 16 bytes): > > 73 65 63 75 72 69 74 79 66 73 00 6b 6b 6b 6b a5 securityfs.kkkk. > > backtrace: > > [<00000000adc80b1b>] kstrdup+0x2e/0x60 > > [<00000000d504cb0d>] ima_parse_add_rule+0x7d4/0x1020 > > [<00000000444825ac>] ima_write_policy+0xab/0x1d0 > > [<000000002b7f0d6c>] vfs_write+0xde/0x1d0 > > [<0000000096feedcf>] ksys_write+0x68/0xe0 > > [<0000000052b544a2>] do_syscall_64+0x56/0xa0 > > [<000000007ead1ba7>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > > > Fixes: f1b08bbcbdaf ("ima: define a new policy condition based on the filesystem name") > > Fixes: 2b60c0ecedf8 ("IMA: Read keyrings= option from the IMA policy") > > Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> > > Your decision, but you might consider squashing this patch with 3/12. > Everything all together in one patch. Oops, that was the comment for 4/12. Mimi
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 1320333201c6..94ca3b8abb69 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -1431,15 +1431,11 @@ ssize_t ima_parse_add_rule(char *rule) void ima_delete_rules(void) { struct ima_rule_entry *entry, *tmp; - int i; temp_ima_appraise = 0; list_for_each_entry_safe(entry, tmp, &ima_temp_rules, list) { - for (i = 0; i < MAX_LSM_RULES; i++) - kfree(entry->lsm[i].args_p); - list_del(&entry->list); - kfree(entry); + ima_free_rule(entry); } }
Use ima_free_rule() to fix memory leaks of allocated ima_rule_entry members, such as .fsname and .keyrings, when deleting a list of rules. This fixes a memory leak seen when loading by a valid rule that contains an additional piece of allocated memory, such as an fsname, followed by an invalid rule that triggers a policy load failure: # echo -e "dont_measure fsname=securityfs\nbad syntax" > \ /sys/kernel/security/ima/policy -bash: echo: write error: Invalid argument # echo scan > /sys/kernel/debug/kmemleak # cat /sys/kernel/debug/kmemleak unreferenced object 0xffff9bab67ca12c0 (size 16): comm "tee", pid 684, jiffies 4295212803 (age 252.344s) hex dump (first 16 bytes): 73 65 63 75 72 69 74 79 66 73 00 6b 6b 6b 6b a5 securityfs.kkkk. backtrace: [<00000000adc80b1b>] kstrdup+0x2e/0x60 [<00000000d504cb0d>] ima_parse_add_rule+0x7d4/0x1020 [<00000000444825ac>] ima_write_policy+0xab/0x1d0 [<000000002b7f0d6c>] vfs_write+0xde/0x1d0 [<0000000096feedcf>] ksys_write+0x68/0xe0 [<0000000052b544a2>] do_syscall_64+0x56/0xa0 [<000000007ead1ba7>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: f1b08bbcbdaf ("ima: define a new policy condition based on the filesystem name") Fixes: 2b60c0ecedf8 ("IMA: Read keyrings= option from the IMA policy") Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> --- security/integrity/ima/ima_policy.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-)