| Message ID | 20220704081839.2232996-1-niejianglei2021@163.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] proc/vmcore: fix potential memory leak in vmcore_init() | expand |
On 07/04/22 at 04:18pm, Jianglei Nie wrote: > elfcorehdr_alloc() allocates a memory chunk for elfcorehdr_addr with > kzalloc(). If is_vmcore_usable() returns false, elfcorehdr_addr is a > predefined value. If parse_crash_elf_headers() occurs some error and > returns a negetive value, the elfcorehdr_addr should be released with > elfcorehdr_free(). > > We can fix by calling elfcorehdr_free() when parse_crash_elf_headers() > fails. LGTM, Acked-by: Baoquan He <bhe@redhat.com> > > Signed-off-by: Jianglei Nie <niejianglei2021@163.com> > --- > fs/proc/vmcore.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c > index 4eaeb645e759..86887bd90263 100644 > --- a/fs/proc/vmcore.c > +++ b/fs/proc/vmcore.c > @@ -1569,7 +1569,7 @@ static int __init vmcore_init(void) > rc = parse_crash_elf_headers(); > if (rc) { > pr_warn("Kdump: vmcore not initialized\n"); > - return rc; > + goto fail; > } > elfcorehdr_free(elfcorehdr_addr); > elfcorehdr_addr = ELFCORE_ADDR_ERR; > @@ -1577,6 +1577,9 @@ static int __init vmcore_init(void) > proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &vmcore_proc_ops); > if (proc_vmcore) > proc_vmcore->size = vmcore_size; > + > +fail: > + elfcorehdr_free(elfcorehdr_addr); > return 0; > } > fs_initcall(vmcore_init); > -- > 2.25.1 >
On 07/08/22 at 04:34pm, Baoquan He wrote: > On 07/04/22 at 04:18pm, Jianglei Nie wrote: > > elfcorehdr_alloc() allocates a memory chunk for elfcorehdr_addr with > > kzalloc(). If is_vmcore_usable() returns false, elfcorehdr_addr is a > > predefined value. If parse_crash_elf_headers() occurs some error and > > returns a negetive value, the elfcorehdr_addr should be released with > > elfcorehdr_free(). > > > > We can fix by calling elfcorehdr_free() when parse_crash_elf_headers() > > fails. > > LGTM, > > Acked-by: Baoquan He <bhe@redhat.com> Sorry, I didn't check the code change carefully. This v2 is not right. I thought Jianglei took my suggested code change directly. Seems he mistakenly took part of them and caused error. > > > > > Signed-off-by: Jianglei Nie <niejianglei2021@163.com> > > --- > > fs/proc/vmcore.c | 5 ++++- > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c > > index 4eaeb645e759..86887bd90263 100644 > > --- a/fs/proc/vmcore.c > > +++ b/fs/proc/vmcore.c > > @@ -1569,7 +1569,7 @@ static int __init vmcore_init(void) > > rc = parse_crash_elf_headers(); > > if (rc) { > > pr_warn("Kdump: vmcore not initialized\n"); > > - return rc; > > + goto fail; > > } > > elfcorehdr_free(elfcorehdr_addr); ~~ this line should be removed. > > elfcorehdr_addr = ELFCORE_ADDR_ERR; > > @@ -1577,6 +1577,9 @@ static int __init vmcore_init(void) > > proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &vmcore_proc_ops); > > if (proc_vmcore) > > proc_vmcore->size = vmcore_size; > > + > > +fail: > > + elfcorehdr_free(elfcorehdr_addr); > > return 0; ^ return rc; the returned value is wrong with v2. What I suggested is as below. Andrew, please drop the one merged into mm-unstable branch. Hi Jianglei, Can you post v3 with below correct change and add Andrew to CC? diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index 4eaeb645e759..390515c249dd 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -1569,15 +1569,16 @@ static int __init vmcore_init(void) rc = parse_crash_elf_headers(); if (rc) { pr_warn("Kdump: vmcore not initialized\n"); - return rc; + goto fail; } - elfcorehdr_free(elfcorehdr_addr); elfcorehdr_addr = ELFCORE_ADDR_ERR; proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &vmcore_proc_ops); if (proc_vmcore) proc_vmcore->size = vmcore_size; - return 0; +fail: + elfcorehdr_free(elfcorehdr_addr); + return rc; } fs_initcall(vmcore_init);
diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index 4eaeb645e759..86887bd90263 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -1569,7 +1569,7 @@ static int __init vmcore_init(void) rc = parse_crash_elf_headers(); if (rc) { pr_warn("Kdump: vmcore not initialized\n"); - return rc; + goto fail; } elfcorehdr_free(elfcorehdr_addr); elfcorehdr_addr = ELFCORE_ADDR_ERR; @@ -1577,6 +1577,9 @@ static int __init vmcore_init(void) proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &vmcore_proc_ops); if (proc_vmcore) proc_vmcore->size = vmcore_size; + +fail: + elfcorehdr_free(elfcorehdr_addr); return 0; } fs_initcall(vmcore_init);
elfcorehdr_alloc() allocates a memory chunk for elfcorehdr_addr with kzalloc(). If is_vmcore_usable() returns false, elfcorehdr_addr is a predefined value. If parse_crash_elf_headers() occurs some error and returns a negetive value, the elfcorehdr_addr should be released with elfcorehdr_free(). We can fix by calling elfcorehdr_free() when parse_crash_elf_headers() fails. Signed-off-by: Jianglei Nie <niejianglei2021@163.com> --- fs/proc/vmcore.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)